Use a new low-memory approach for tf dataset index shuffling

This PR tries out a new approach to generating the index tensor in `to_tf_dataset`, which should reduce memory usage for very large datasets. I'll need to do some testing before merging it!

Fixes #5855


The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/datasets/pr_5863). All of your documentation changes will be reflected on that endpoint.

<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.007764 / 0.011353 (-0.003588) | 0.005397 / 0.011008 (-0.005611) | 0.097995 / 0.038508 (0.059487) | 0.036360 / 0.023109 (0.013251) | 0.312148 / 0.275898 (0.036250) | 0.349427 / 0.323480 (0.025947) | 0.006635 / 0.007986 (-0.001350) | 0.004373 / 0.004328 (0.000044) | 0.074350 / 0.004250 (0.070099) | 0.054667 / 0.037052 (0.017614) | 0.301621 / 0.258489 (0.043132) | 0.364233 / 0.293841 (0.070392) | 0.035356 / 0.128546 (-0.093191) | 0.012512 / 0.075646 (-0.063134) | 0.333399 / 0.419271 (-0.085873) | 0.051363 / 0.043533 (0.007830) | 0.302372 / 0.255139 (0.047233) | 0.326542 / 0.283200 (0.043343) | 0.118610 / 0.141683 (-0.023073) | 1.438485 / 1.452155 (-0.013669) | 1.539131 / 1.492716 (0.046415) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.010920 / 0.018006 (-0.007086) | 0.561263 / 0.000490 (0.560773) | 0.003972 / 0.000200 (0.003772) | 0.000096 / 0.000054 (0.000042) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.030333 / 0.037411 (-0.007078) | 0.113608 / 0.014526 (0.099083) | 0.125802 / 0.176557 (-0.050755) | 0.183885 / 0.737135 (-0.553250) | 0.130242 / 0.296338 (-0.166097) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.404147 / 0.215209 (0.188938) | 4.021990 / 2.077655 (1.944335) | 1.821450 / 1.504120 (0.317330) | 1.619032 / 1.541195 (0.077837) | 1.791267 / 1.468490 (0.322777) | 0.706683 / 4.584777 (-3.878094) | 3.819056 / 3.745712 (0.073344) | 3.485714 / 5.269862 (-1.784147) | 1.938968 / 4.565676 (-2.626709) | 0.086501 / 0.424275 (-0.337774) | 0.012300 / 0.007607 (0.004693) | 0.503600 / 0.226044 (0.277555) | 5.042123 / 2.268929 (2.773195) | 2.269712 / 55.444624 (-53.174912) | 1.944912 / 6.876477 (-4.931565) | 2.155196 / 2.142072 (0.013123) | 0.853434 / 4.805227 (-3.951793) | 0.175554 / 6.500664 (-6.325110) | 0.072005 / 0.075469 (-0.003464) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.203765 / 1.841788 (-0.638022) | 15.836634 / 8.074308 (7.762326) | 15.707348 / 10.191392 (5.515956) | 0.164828 / 0.680424 (-0.515596) | 0.018115 / 0.534201 (-0.516086) | 0.434591 / 0.579283 (-0.144692) | 0.437858 / 0.434364 (0.003495) | 0.524672 / 0.540337 (-0.015665) | 0.610535 / 1.386936 (-0.776401) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.007558 / 0.011353 (-0.003795) | 0.005258 / 0.011008 (-0.005750) | 0.075263 / 0.038508 (0.036755) | 0.033915 / 0.023109 (0.010805) | 0.371368 / 0.275898 (0.095470) | 0.399239 / 0.323480 (0.075760) | 0.006547 / 0.007986 (-0.001439) | 0.004675 / 0.004328 (0.000347) | 0.074230 / 0.004250 (0.069980) | 0.054653 / 0.037052 (0.017601) | 0.376655 / 0.258489 (0.118166) | 0.438437 / 0.293841 (0.144596) | 0.035838 / 0.128546 (-0.092709) | 0.012641 / 0.075646 (-0.063005) | 0.087279 / 0.419271 (-0.331993) | 0.046311 / 0.043533 (0.002778) | 0.356649 / 0.255139 (0.101510) | 0.377876 / 0.283200 (0.094677) | 0.108097 / 0.141683 (-0.033586) | 1.478461 / 1.452155 (0.026306) | 1.560375 / 1.492716 (0.067658) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.316384 / 0.018006 (0.298378) | 0.539382 / 0.000490 (0.538892) | 0.002029 / 0.000200 (0.001829) | 0.000090 / 0.000054 (0.000036) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.029950 / 0.037411 (-0.007462) | 0.111371 / 0.014526 (0.096846) | 0.125254 / 0.176557 (-0.051303) | 0.173064 / 0.737135 (-0.564071) | 0.130446 / 0.296338 (-0.165893) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.424882 / 0.215209 (0.209673) | 4.241575 / 2.077655 (2.163920) | 2.096216 / 1.504120 (0.592096) | 1.916017 / 1.541195 (0.374823) | 2.016318 / 1.468490 (0.547828) | 0.701197 / 4.584777 (-3.883580) | 3.762365 / 3.745712 (0.016652) | 3.307805 / 5.269862 (-1.962057) | 1.841752 / 4.565676 (-2.723925) | 0.086003 / 0.424275 (-0.338272) | 0.012247 / 0.007607 (0.004640) | 0.532926 / 0.226044 (0.306882) | 5.370509 / 2.268929 (3.101580) | 2.587853 / 55.444624 (-52.856772) | 2.264541 / 6.876477 (-4.611936) | 2.374833 / 2.142072 (0.232760) | 0.827751 / 4.805227 (-3.977476) | 0.169454 / 6.500664 (-6.331210) | 0.066340 / 0.075469 (-0.009129) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.319128 / 1.841788 (-0.522660) | 16.702085 / 8.074308 (8.627777) | 13.559957 / 10.191392 (3.368565) | 0.146659 / 0.680424 (-0.533765) | 0.017384 / 0.534201 (-0.516817) | 0.421126 / 0.579283 (-0.158157) | 0.422067 / 0.434364 (-0.012297) | 0.490615 / 0.540337 (-0.049723) | 0.587151 / 1.386936 (-0.799785) |

</details>
</details>

![](https://cml.dev/watermark.png#79f4b6de25128999f5fc0a7bde9aa71c461f518f "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.006604 / 0.011353 (-0.004749) | 0.004508 / 0.011008 (-0.006500) | 0.098652 / 0.038508 (0.060144) | 0.028172 / 0.023109 (0.005063) | 0.366997 / 0.275898 (0.091099) | 0.403691 / 0.323480 (0.080211) | 0.005127 / 0.007986 (-0.002859) | 0.003340 / 0.004328 (-0.000989) | 0.075408 / 0.004250 (0.071157) | 0.038049 / 0.037052 (0.000996) | 0.367914 / 0.258489 (0.109425) | 0.410958 / 0.293841 (0.117118) | 0.030454 / 0.128546 (-0.098093) | 0.011422 / 0.075646 (-0.064224) | 0.325048 / 0.419271 (-0.094223) | 0.042959 / 0.043533 (-0.000574) | 0.374536 / 0.255139 (0.119397) | 0.394738 / 0.283200 (0.111538) | 0.090481 / 0.141683 (-0.051201) | 1.504858 / 1.452155 (0.052703) | 1.569072 / 1.492716 (0.076356) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.010062 / 0.018006 (-0.007945) | 0.408619 / 0.000490 (0.408130) | 0.002307 / 0.000200 (0.002107) | 0.000070 / 0.000054 (0.000016) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.022898 / 0.037411 (-0.014514) | 0.096975 / 0.014526 (0.082449) | 0.103032 / 0.176557 (-0.073524) | 0.164877 / 0.737135 (-0.572259) | 0.107324 / 0.296338 (-0.189014) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.446652 / 0.215209 (0.231442) | 4.466939 / 2.077655 (2.389285) | 2.204590 / 1.504120 (0.700471) | 2.004048 / 1.541195 (0.462853) | 2.053035 / 1.468490 (0.584545) | 0.696617 / 4.584777 (-3.888160) | 3.391173 / 3.745712 (-0.354539) | 1.863306 / 5.269862 (-3.406556) | 1.160637 / 4.565676 (-3.405039) | 0.083115 / 0.424275 (-0.341160) | 0.012470 / 0.007607 (0.004862) | 0.547207 / 0.226044 (0.321163) | 5.500667 / 2.268929 (3.231739) | 2.656615 / 55.444624 (-52.788009) | 2.313281 / 6.876477 (-4.563195) | 2.395632 / 2.142072 (0.253559) | 0.815361 / 4.805227 (-3.989867) | 0.152112 / 6.500664 (-6.348552) | 0.067485 / 0.075469 (-0.007984) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.206975 / 1.841788 (-0.634813) | 13.684136 / 8.074308 (5.609828) | 13.919129 / 10.191392 (3.727737) | 0.140767 / 0.680424 (-0.539657) | 0.016445 / 0.534201 (-0.517756) | 0.379136 / 0.579283 (-0.200147) | 0.385395 / 0.434364 (-0.048969) | 0.445781 / 0.540337 (-0.094556) | 0.522056 / 1.386936 (-0.864880) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.006370 / 0.011353 (-0.004983) | 0.004514 / 0.011008 (-0.006495) | 0.075671 / 0.038508 (0.037163) | 0.026723 / 0.023109 (0.003614) | 0.359819 / 0.275898 (0.083921) | 0.387935 / 0.323480 (0.064456) | 0.004888 / 0.007986 (-0.003098) | 0.004619 / 0.004328 (0.000290) | 0.075546 / 0.004250 (0.071295) | 0.039024 / 0.037052 (0.001971) | 0.361173 / 0.258489 (0.102684) | 0.411425 / 0.293841 (0.117584) | 0.030842 / 0.128546 (-0.097705) | 0.011555 / 0.075646 (-0.064091) | 0.084697 / 0.419271 (-0.334574) | 0.039281 / 0.043533 (-0.004252) | 0.370082 / 0.255139 (0.114943) | 0.382113 / 0.283200 (0.098913) | 0.091237 / 0.141683 (-0.050445) | 1.534185 / 1.452155 (0.082030) | 1.576488 / 1.492716 (0.083772) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.226568 / 0.018006 (0.208562) | 0.401566 / 0.000490 (0.401076) | 0.002915 / 0.000200 (0.002715) | 0.000076 / 0.000054 (0.000022) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.025357 / 0.037411 (-0.012054) | 0.099747 / 0.014526 (0.085221) | 0.106443 / 0.176557 (-0.070113) | 0.157147 / 0.737135 (-0.579989) | 0.110759 / 0.296338 (-0.185580) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.444648 / 0.215209 (0.229439) | 4.437930 / 2.077655 (2.360275) | 2.154033 / 1.504120 (0.649913) | 1.958351 / 1.541195 (0.417157) | 1.991031 / 1.468490 (0.522541) | 0.691440 / 4.584777 (-3.893337) | 3.369087 / 3.745712 (-0.376625) | 1.847103 / 5.269862 (-3.422758) | 1.152509 / 4.565676 (-3.413168) | 0.082519 / 0.424275 (-0.341756) | 0.012609 / 0.007607 (0.005001) | 0.547267 / 0.226044 (0.321222) | 5.501335 / 2.268929 (3.232407) | 2.621079 / 55.444624 (-52.823545) | 2.281332 / 6.876477 (-4.595145) | 2.300427 / 2.142072 (0.158354) | 0.803611 / 4.805227 (-4.001616) | 0.151784 / 6.500664 (-6.348880) | 0.067801 / 0.075469 (-0.007669) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.343201 / 1.841788 (-0.498587) | 13.901033 / 8.074308 (5.826725) | 13.114738 / 10.191392 (2.923346) | 0.149358 / 0.680424 (-0.531066) | 0.016596 / 0.534201 (-0.517605) | 0.377310 / 0.579283 (-0.201973) | 0.387045 / 0.434364 (-0.047319) | 0.441272 / 0.540337 (-0.099065) | 0.525783 / 1.386936 (-0.861153) |

</details>
</details>

![](https://cml.dev/watermark.png#c127e5575ab4e22648976ad268d76264ef5d04f8 "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008147 / 0.011353 (-0.003205) | 0.005531 / 0.011008 (-0.005477) | 0.099796 / 0.038508 (0.061288) | 0.041574 / 0.023109 (0.018465) | 0.315752 / 0.275898 (0.039854) | 0.369846 / 0.323480 (0.046366) | 0.006489 / 0.007986 (-0.001497) | 0.004339 / 0.004328 (0.000010) | 0.074769 / 0.004250 (0.070519) | 0.051313 / 0.037052 (0.014261) | 0.313463 / 0.258489 (0.054974) | 0.369918 / 0.293841 (0.076077) | 0.035893 / 0.128546 (-0.092653) | 0.012487 / 0.075646 (-0.063159) | 0.336464 / 0.419271 (-0.082807) | 0.052870 / 0.043533 (0.009337) | 0.310795 / 0.255139 (0.055656) | 0.333146 / 0.283200 (0.049946) | 0.112813 / 0.141683 (-0.028870) | 1.488192 / 1.452155 (0.036038) | 1.563438 / 1.492716 (0.070721) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.015015 / 0.018006 (-0.002991) | 0.531783 / 0.000490 (0.531294) | 0.005039 / 0.000200 (0.004839) | 0.000103 / 0.000054 (0.000049) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.030205 / 0.037411 (-0.007207) | 0.115997 / 0.014526 (0.101471) | 0.122958 / 0.176557 (-0.053599) | 0.186956 / 0.737135 (-0.550180) | 0.130268 / 0.296338 (-0.166071) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.402648 / 0.215209 (0.187439) | 3.996121 / 2.077655 (1.918466) | 1.811715 / 1.504120 (0.307595) | 1.640805 / 1.541195 (0.099610) | 1.810478 / 1.468490 (0.341988) | 0.699996 / 4.584777 (-3.884781) | 3.834020 / 3.745712 (0.088308) | 3.688364 / 5.269862 (-1.581498) | 1.973828 / 4.565676 (-2.591849) | 0.087085 / 0.424275 (-0.337190) | 0.012501 / 0.007607 (0.004894) | 0.498934 / 0.226044 (0.272889) | 4.977608 / 2.268929 (2.708680) | 2.258678 / 55.444624 (-53.185947) | 1.934251 / 6.876477 (-4.942226) | 2.177409 / 2.142072 (0.035337) | 0.873470 / 4.805227 (-3.931757) | 0.173132 / 6.500664 (-6.327532) | 0.069144 / 0.075469 (-0.006325) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.181554 / 1.841788 (-0.660234) | 15.694468 / 8.074308 (7.620160) | 15.026954 / 10.191392 (4.835562) | 0.167092 / 0.680424 (-0.513332) | 0.017921 / 0.534201 (-0.516280) | 0.425649 / 0.579283 (-0.153634) | 0.423225 / 0.434364 (-0.011139) | 0.522132 / 0.540337 (-0.018205) | 0.612806 / 1.386936 (-0.774130) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.007896 / 0.011353 (-0.003457) | 0.005581 / 0.011008 (-0.005427) | 0.076338 / 0.038508 (0.037830) | 0.037064 / 0.023109 (0.013954) | 0.399706 / 0.275898 (0.123808) | 0.431698 / 0.323480 (0.108218) | 0.006846 / 0.007986 (-0.001140) | 0.006010 / 0.004328 (0.001682) | 0.075771 / 0.004250 (0.071520) | 0.058214 / 0.037052 (0.021161) | 0.395753 / 0.258489 (0.137264) | 0.459925 / 0.293841 (0.166084) | 0.036349 / 0.128546 (-0.092197) | 0.012720 / 0.075646 (-0.062926) | 0.087248 / 0.419271 (-0.332024) | 0.049405 / 0.043533 (0.005872) | 0.387576 / 0.255139 (0.132437) | 0.409861 / 0.283200 (0.126661) | 0.111639 / 0.141683 (-0.030043) | 1.482840 / 1.452155 (0.030685) | 1.574465 / 1.492716 (0.081749) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.320628 / 0.018006 (0.302622) | 0.556338 / 0.000490 (0.555848) | 0.000445 / 0.000200 (0.000245) | 0.000060 / 0.000054 (0.000006) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.032905 / 0.037411 (-0.004507) | 0.121253 / 0.014526 (0.106727) | 0.127241 / 0.176557 (-0.049316) | 0.178090 / 0.737135 (-0.559045) | 0.143285 / 0.296338 (-0.153054) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.437852 / 0.215209 (0.222643) | 4.369770 / 2.077655 (2.292115) | 2.219932 / 1.504120 (0.715812) | 2.032520 / 1.541195 (0.491325) | 2.154300 / 1.468490 (0.685810) | 0.678942 / 4.584777 (-3.905835) | 3.768148 / 3.745712 (0.022436) | 2.152738 / 5.269862 (-3.117124) | 1.341480 / 4.565676 (-3.224197) | 0.084326 / 0.424275 (-0.339949) | 0.012288 / 0.007607 (0.004681) | 0.547677 / 0.226044 (0.321633) | 5.496777 / 2.268929 (3.227848) | 2.702267 / 55.444624 (-52.742357) | 2.388580 / 6.876477 (-4.487897) | 2.471673 / 2.142072 (0.329601) | 0.833645 / 4.805227 (-3.971582) | 0.167113 / 6.500664 (-6.333551) | 0.067658 / 0.075469 (-0.007811) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.282050 / 1.841788 (-0.559737) | 16.413677 / 8.074308 (8.339369) | 14.080910 / 10.191392 (3.889518) | 0.171782 / 0.680424 (-0.508642) | 0.018186 / 0.534201 (-0.516015) | 0.425244 / 0.579283 (-0.154039) | 0.430260 / 0.434364 (-0.004104) | 0.500838 / 0.540337 (-0.039499) | 0.591900 / 1.386936 (-0.795036) |

</details>
</details>

![](https://cml.dev/watermark.png#5fc5c538de84da400118e3712077acc580ce85c4 "CML watermark")


The approach we take here is to no longer materialize the entire index array or shuffle buffer. Instead, we do the following:

1) Generate a dataset with `tf.data.Dataset.range`. This dataset is not materialized - it's basically a range iterator.
2) When we begin iterating over a dataset, generate a random seed. This value is constant for each pass over the dataset, and is regenerated if we start a new iteration or epoch over the dataset.
3) Map the range dataset and the random seed with `tf.random.index_shuffle`. This converts indices into the equivalent values in a permuted array. In other words `tf.random.index_shuffle(indices, maxval=50_000_000)` is equivalent to `np.random.permutation(50_000_000)[indices]`, but without ever materializing the `np.random.permutation(50_000_000)` array.

Using this approach gives us a complete iteration over the dataset that does not skip any samples, compiles in TF and also never materializes the complete index array, which should avoid the memory usage issues. I'm testing that now!

<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008395 / 0.011353 (-0.002958) | 0.005893 / 0.011008 (-0.005115) | 0.117081 / 0.038508 (0.078573) | 0.040987 / 0.023109 (0.017878) | 0.394234 / 0.275898 (0.118336) | 0.447036 / 0.323480 (0.123556) | 0.006703 / 0.007986 (-0.001283) | 0.006085 / 0.004328 (0.001757) | 0.086479 / 0.004250 (0.082228) | 0.050192 / 0.037052 (0.013140) | 0.400958 / 0.258489 (0.142469) | 0.455551 / 0.293841 (0.161710) | 0.041481 / 0.128546 (-0.087065) | 0.014135 / 0.075646 (-0.061511) | 0.399929 / 0.419271 (-0.019343) | 0.060824 / 0.043533 (0.017291) | 0.395946 / 0.255139 (0.140807) | 0.428811 / 0.283200 (0.145611) | 0.120057 / 0.141683 (-0.021626) | 1.703244 / 1.452155 (0.251090) | 1.841153 / 1.492716 (0.348436) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.021826 / 0.018006 (0.003820) | 0.494279 / 0.000490 (0.493789) | 0.011258 / 0.000200 (0.011058) | 0.000382 / 0.000054 (0.000328) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.031651 / 0.037411 (-0.005760) | 0.132871 / 0.014526 (0.118345) | 0.137388 / 0.176557 (-0.039169) | 0.205808 / 0.737135 (-0.531327) | 0.147585 / 0.296338 (-0.148753) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.474483 / 0.215209 (0.259274) | 4.726568 / 2.077655 (2.648914) | 2.136172 / 1.504120 (0.632052) | 1.918364 / 1.541195 (0.377169) | 2.068794 / 1.468490 (0.600304) | 0.836481 / 4.584777 (-3.748296) | 4.550583 / 3.745712 (0.804871) | 2.456287 / 5.269862 (-2.813574) | 1.563127 / 4.565676 (-3.002550) | 0.102541 / 0.424275 (-0.321734) | 0.014492 / 0.007607 (0.006885) | 0.598572 / 0.226044 (0.372528) | 5.953321 / 2.268929 (3.684392) | 2.695210 / 55.444624 (-52.749414) | 2.294317 / 6.876477 (-4.582160) | 2.456585 / 2.142072 (0.314513) | 1.019907 / 4.805227 (-3.785320) | 0.201225 / 6.500664 (-6.299439) | 0.077113 / 0.075469 (0.001644) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.497662 / 1.841788 (-0.344126) | 18.216941 / 8.074308 (10.142633) | 17.016638 / 10.191392 (6.825246) | 0.193271 / 0.680424 (-0.487153) | 0.020440 / 0.534201 (-0.513761) | 0.509361 / 0.579283 (-0.069922) | 0.513389 / 0.434364 (0.079025) | 0.622266 / 0.540337 (0.081928) | 0.741733 / 1.386936 (-0.645203) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008641 / 0.011353 (-0.002712) | 0.005792 / 0.011008 (-0.005216) | 0.086020 / 0.038508 (0.047512) | 0.040005 / 0.023109 (0.016896) | 0.435120 / 0.275898 (0.159222) | 0.480269 / 0.323480 (0.156789) | 0.006669 / 0.007986 (-0.001317) | 0.006039 / 0.004328 (0.001711) | 0.083468 / 0.004250 (0.079218) | 0.057700 / 0.037052 (0.020648) | 0.416418 / 0.258489 (0.157929) | 0.508286 / 0.293841 (0.214445) | 0.041198 / 0.128546 (-0.087349) | 0.014346 / 0.075646 (-0.061301) | 0.100553 / 0.419271 (-0.318718) | 0.054201 / 0.043533 (0.010668) | 0.438232 / 0.255139 (0.183093) | 0.454707 / 0.283200 (0.171508) | 0.118332 / 0.141683 (-0.023351) | 1.657607 / 1.452155 (0.205452) | 1.825510 / 1.492716 (0.332794) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.236156 / 0.018006 (0.218150) | 0.487612 / 0.000490 (0.487123) | 0.005747 / 0.000200 (0.005547) | 0.000111 / 0.000054 (0.000057) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.035127 / 0.037411 (-0.002284) | 0.132013 / 0.014526 (0.117487) | 0.142316 / 0.176557 (-0.034241) | 0.198627 / 0.737135 (-0.538508) | 0.145454 / 0.296338 (-0.150885) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.513041 / 0.215209 (0.297832) | 5.066197 / 2.077655 (2.988542) | 2.508779 / 1.504120 (1.004659) | 2.273901 / 1.541195 (0.732706) | 2.364958 / 1.468490 (0.896468) | 0.811367 / 4.584777 (-3.773410) | 4.504744 / 3.745712 (0.759032) | 2.499811 / 5.269862 (-2.770050) | 1.583349 / 4.565676 (-2.982328) | 0.101701 / 0.424275 (-0.322574) | 0.014379 / 0.007607 (0.006772) | 0.669506 / 0.226044 (0.443462) | 6.556702 / 2.268929 (4.287774) | 3.123457 / 55.444624 (-52.321167) | 2.731997 / 6.876477 (-4.144480) | 2.862866 / 2.142072 (0.720794) | 0.992956 / 4.805227 (-3.812271) | 0.200473 / 6.500664 (-6.300191) | 0.078780 / 0.075469 (0.003311) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.540718 / 1.841788 (-0.301070) | 18.749344 / 8.074308 (10.675036) | 15.648983 / 10.191392 (5.457591) | 0.174089 / 0.680424 (-0.506335) | 0.020441 / 0.534201 (-0.513760) | 0.503742 / 0.579283 (-0.075541) | 0.500648 / 0.434364 (0.066284) | 0.598558 / 0.540337 (0.058221) | 0.712093 / 1.386936 (-0.674843) |

</details>
</details>

![](https://cml.dev/watermark.png#621554280f964b5fe87ece1a46b794406d943b1e "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.009940 / 0.011353 (-0.001412) | 0.006193 / 0.011008 (-0.004815) | 0.125874 / 0.038508 (0.087366) | 0.038664 / 0.023109 (0.015555) | 0.380013 / 0.275898 (0.104115) | 0.430152 / 0.323480 (0.106672) | 0.006961 / 0.007986 (-0.001025) | 0.004749 / 0.004328 (0.000420) | 0.099743 / 0.004250 (0.095492) | 0.052349 / 0.037052 (0.015297) | 0.433354 / 0.258489 (0.174865) | 0.436273 / 0.293841 (0.142433) | 0.053929 / 0.128546 (-0.074617) | 0.019369 / 0.075646 (-0.056278) | 0.421783 / 0.419271 (0.002511) | 0.062746 / 0.043533 (0.019213) | 0.377225 / 0.255139 (0.122086) | 0.413708 / 0.283200 (0.130508) | 0.111371 / 0.141683 (-0.030312) | 1.819166 / 1.452155 (0.367011) | 1.974527 / 1.492716 (0.481810) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.090664 / 0.018006 (0.072658) | 0.566166 / 0.000490 (0.565676) | 0.079305 / 0.000200 (0.079105) | 0.000755 / 0.000054 (0.000700) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.029720 / 0.037411 (-0.007691) | 0.126030 / 0.014526 (0.111504) | 0.146020 / 0.176557 (-0.030537) | 0.210354 / 0.737135 (-0.526781) | 0.149428 / 0.296338 (-0.146910) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.624371 / 0.215209 (0.409162) | 6.332839 / 2.077655 (4.255184) | 2.547784 / 1.504120 (1.043664) | 2.150508 / 1.541195 (0.609313) | 2.240816 / 1.468490 (0.772326) | 1.271131 / 4.584777 (-3.313646) | 5.642726 / 3.745712 (1.897014) | 3.212988 / 5.269862 (-2.056874) | 2.258123 / 4.565676 (-2.307553) | 0.149477 / 0.424275 (-0.274798) | 0.014603 / 0.007607 (0.006996) | 0.782155 / 0.226044 (0.556111) | 7.855191 / 2.268929 (5.586262) | 3.308638 / 55.444624 (-52.135986) | 2.548142 / 6.876477 (-4.328335) | 2.627374 / 2.142072 (0.485301) | 1.515170 / 4.805227 (-3.290058) | 0.262479 / 6.500664 (-6.238185) | 0.082181 / 0.075469 (0.006712) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.573169 / 1.841788 (-0.268618) | 18.105719 / 8.074308 (10.031411) | 22.015179 / 10.191392 (11.823787) | 0.254678 / 0.680424 (-0.425746) | 0.027098 / 0.534201 (-0.507103) | 0.578045 / 0.579283 (-0.001238) | 0.647130 / 0.434364 (0.212766) | 0.650522 / 0.540337 (0.110185) | 0.797713 / 1.386936 (-0.589223) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.010376 / 0.011353 (-0.000977) | 0.005990 / 0.011008 (-0.005018) | 0.097144 / 0.038508 (0.058635) | 0.038205 / 0.023109 (0.015096) | 0.468347 / 0.275898 (0.192449) | 0.497646 / 0.323480 (0.174166) | 0.006916 / 0.007986 (-0.001069) | 0.004760 / 0.004328 (0.000431) | 0.109838 / 0.004250 (0.105587) | 0.048321 / 0.037052 (0.011269) | 0.437458 / 0.258489 (0.178969) | 0.534864 / 0.293841 (0.241023) | 0.053655 / 0.128546 (-0.074892) | 0.021915 / 0.075646 (-0.053732) | 0.121047 / 0.419271 (-0.298224) | 0.059694 / 0.043533 (0.016162) | 0.466937 / 0.255139 (0.211798) | 0.482030 / 0.283200 (0.198831) | 0.117458 / 0.141683 (-0.024225) | 1.835551 / 1.452155 (0.383396) | 1.965748 / 1.492716 (0.473031) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.234885 / 0.018006 (0.216879) | 0.529925 / 0.000490 (0.529436) | 0.000484 / 0.000200 (0.000284) | 0.000085 / 0.000054 (0.000031) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.030959 / 0.037411 (-0.006453) | 0.128905 / 0.014526 (0.114379) | 0.136913 / 0.176557 (-0.039643) | 0.195133 / 0.737135 (-0.542002) | 0.147929 / 0.296338 (-0.148410) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.715661 / 0.215209 (0.500451) | 6.994125 / 2.077655 (4.916470) | 3.033178 / 1.504120 (1.529058) | 2.663709 / 1.541195 (1.122515) | 2.707558 / 1.468490 (1.239068) | 1.316195 / 4.584777 (-3.268582) | 5.688264 / 3.745712 (1.942552) | 3.260897 / 5.269862 (-2.008964) | 2.134985 / 4.565676 (-2.430691) | 0.153945 / 0.424275 (-0.270330) | 0.014727 / 0.007607 (0.007119) | 0.911339 / 0.226044 (0.685294) | 8.902640 / 2.268929 (6.633711) | 3.806606 / 55.444624 (-51.638018) | 3.052238 / 6.876477 (-3.824238) | 3.046945 / 2.142072 (0.904873) | 1.559837 / 4.805227 (-3.245390) | 0.272276 / 6.500664 (-6.228388) | 0.087728 / 0.075469 (0.012259) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.712691 / 1.841788 (-0.129097) | 18.127575 / 8.074308 (10.053267) | 19.734063 / 10.191392 (9.542671) | 0.235006 / 0.680424 (-0.445418) | 0.027581 / 0.534201 (-0.506620) | 0.551080 / 0.579283 (-0.028203) | 0.608564 / 0.434364 (0.174200) | 0.636578 / 0.540337 (0.096241) | 0.732374 / 1.386936 (-0.654562) |

</details>
</details>

![](https://cml.dev/watermark.png#36911ca06d9c4e37ce36da6228cb3af8b40c2add "CML watermark")


Looks good in testing - this should be ready for review! cc @lhoestq @massquantity

Looks good to me, though i doubt that very few people will upgrade to TF >= 2.9 unless their memory is full:)

Is it more efficient than using numpy to shuffle as in multiprocessing ? Why not use the same strategy ?

Good question, honestly! The NumPy strategy works fine, but requires us to handle multiple processes instead of doing everything in `tf.data`. We could just scrap this entire code path and always use the multiprocessing NumPy approach, but I think single-threaded throughput would be lower if we did that. If you prefer it for code simplicity, though, I can do that.

In the longer term, I'm hoping that `tf.data` gets native support for our data structures and we can transition the whole pipeline to pure `tf.data`, but that still hasn't happened 🫠

And @massquantity TF 2.13 is going to release in a couple of days, so I hope most users are at least on TF 2.9 by now!

Unless there is a big gap in performance I think code simplicity would be appreciated ^^

<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008638 / 0.011353 (-0.002715) | 0.006013 / 0.011008 (-0.004995) | 0.116456 / 0.038508 (0.077948) | 0.040419 / 0.023109 (0.017310) | 0.418374 / 0.275898 (0.142476) | 0.447693 / 0.323480 (0.124213) | 0.007002 / 0.007986 (-0.000984) | 0.006175 / 0.004328 (0.001847) | 0.087801 / 0.004250 (0.083550) | 0.051980 / 0.037052 (0.014928) | 0.393275 / 0.258489 (0.134786) | 0.449601 / 0.293841 (0.155760) | 0.041670 / 0.128546 (-0.086876) | 0.014396 / 0.075646 (-0.061251) | 0.399175 / 0.419271 (-0.020096) | 0.060635 / 0.043533 (0.017102) | 0.391449 / 0.255139 (0.136310) | 0.420713 / 0.283200 (0.137513) | 0.121369 / 0.141683 (-0.020314) | 1.692630 / 1.452155 (0.240475) | 1.815526 / 1.492716 (0.322810) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.244321 / 0.018006 (0.226315) | 0.487947 / 0.000490 (0.487458) | 0.004563 / 0.000200 (0.004363) | 0.000116 / 0.000054 (0.000061) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.033425 / 0.037411 (-0.003987) | 0.134458 / 0.014526 (0.119932) | 0.138810 / 0.176557 (-0.037746) | 0.208871 / 0.737135 (-0.528264) | 0.147964 / 0.296338 (-0.148374) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.483347 / 0.215209 (0.268138) | 4.799550 / 2.077655 (2.721895) | 2.174149 / 1.504120 (0.670029) | 1.943276 / 1.541195 (0.402081) | 2.010884 / 1.468490 (0.542394) | 0.832030 / 4.584777 (-3.752747) | 4.716713 / 3.745712 (0.971001) | 4.615810 / 5.269862 (-0.654052) | 2.379600 / 4.565676 (-2.186077) | 0.103560 / 0.424275 (-0.320715) | 0.014683 / 0.007607 (0.007076) | 0.598558 / 0.226044 (0.372514) | 5.999126 / 2.268929 (3.730197) | 2.677819 / 55.444624 (-52.766805) | 2.320838 / 6.876477 (-4.555639) | 2.503684 / 2.142072 (0.361611) | 1.016459 / 4.805227 (-3.788769) | 0.201672 / 6.500664 (-6.298992) | 0.079310 / 0.075469 (0.003841) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.446374 / 1.841788 (-0.395413) | 19.219310 / 8.074308 (11.145002) | 17.294665 / 10.191392 (7.103273) | 0.246115 / 0.680424 (-0.434309) | 0.021406 / 0.534201 (-0.512795) | 0.524084 / 0.579283 (-0.055200) | 0.511254 / 0.434364 (0.076890) | 0.621304 / 0.540337 (0.080966) | 0.727088 / 1.386936 (-0.659848) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008907 / 0.011353 (-0.002446) | 0.006165 / 0.011008 (-0.004843) | 0.090786 / 0.038508 (0.052278) | 0.040893 / 0.023109 (0.017784) | 0.451252 / 0.275898 (0.175354) | 0.477811 / 0.323480 (0.154331) | 0.007418 / 0.007986 (-0.000568) | 0.005789 / 0.004328 (0.001461) | 0.087422 / 0.004250 (0.083171) | 0.061800 / 0.037052 (0.024748) | 0.459085 / 0.258489 (0.200596) | 0.488897 / 0.293841 (0.195056) | 0.048157 / 0.128546 (-0.080389) | 0.014676 / 0.075646 (-0.060970) | 0.104372 / 0.419271 (-0.314900) | 0.058066 / 0.043533 (0.014534) | 0.446131 / 0.255139 (0.190992) | 0.460428 / 0.283200 (0.177228) | 0.128492 / 0.141683 (-0.013191) | 1.811419 / 1.452155 (0.359265) | 1.894781 / 1.492716 (0.402064) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.220527 / 0.018006 (0.202520) | 0.487663 / 0.000490 (0.487173) | 0.003864 / 0.000200 (0.003664) | 0.000162 / 0.000054 (0.000107) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.036354 / 0.037411 (-0.001057) | 0.140469 / 0.014526 (0.125944) | 0.149990 / 0.176557 (-0.026566) | 0.212369 / 0.737135 (-0.524766) | 0.154000 / 0.296338 (-0.142338) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.514172 / 0.215209 (0.298963) | 5.129247 / 2.077655 (3.051593) | 2.536773 / 1.504120 (1.032653) | 2.317253 / 1.541195 (0.776058) | 2.424066 / 1.468490 (0.955576) | 0.836160 / 4.584777 (-3.748617) | 4.906235 / 3.745712 (1.160523) | 4.431395 / 5.269862 (-0.838467) | 2.332845 / 4.565676 (-2.232831) | 0.102867 / 0.424275 (-0.321409) | 0.014851 / 0.007607 (0.007244) | 0.644104 / 0.226044 (0.418060) | 6.415847 / 2.268929 (4.146918) | 3.186984 / 55.444624 (-52.257641) | 2.774125 / 6.876477 (-4.102352) | 2.848045 / 2.142072 (0.705972) | 1.018757 / 4.805227 (-3.786470) | 0.212333 / 6.500664 (-6.288331) | 0.079405 / 0.075469 (0.003936) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.748375 / 1.841788 (-0.093412) | 19.733829 / 8.074308 (11.659521) | 15.766665 / 10.191392 (5.575273) | 0.192087 / 0.680424 (-0.488337) | 0.027641 / 0.534201 (-0.506560) | 0.504101 / 0.579283 (-0.075182) | 0.493815 / 0.434364 (0.059451) | 0.583247 / 0.540337 (0.042910) | 0.697432 / 1.386936 (-0.689504) |

</details>
</details>

![](https://cml.dev/watermark.png#95c177e02ca20bf7bb3ed8f185d2d6f05a5e5f30 "CML watermark")


Hi @lhoestq, I tried moving everything to the NumPy path but ran into issues - the `SharedMemory` constructs it depends on were only added in Python 3.8. As a result, if we move everything to that path then `to_tf_dataset` does not work on older Python versions.

For now, how do you feel about reverting and using my original solution, which has fallbacks for all versions of Python and TensorFlow? Once our minimum versions pass Python 3.8 or TF 2.9 we can remove the older code paths.

Gentle ping on this question @lhoestq!

Ah yes indeed. Feel free to revert and add comments to explain why you needed to have a different approach for single process

<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008395 / 0.011353 (-0.002958) | 0.005773 / 0.011008 (-0.005235) | 0.115702 / 0.038508 (0.077194) | 0.039897 / 0.023109 (0.016788) | 0.483140 / 0.275898 (0.207242) | 0.531288 / 0.323480 (0.207808) | 0.006739 / 0.007986 (-0.001246) | 0.004419 / 0.004328 (0.000090) | 0.086374 / 0.004250 (0.082124) | 0.056498 / 0.037052 (0.019446) | 0.491589 / 0.258489 (0.233100) | 0.556366 / 0.293841 (0.262525) | 0.041366 / 0.128546 (-0.087181) | 0.014373 / 0.075646 (-0.061274) | 0.395504 / 0.419271 (-0.023767) | 0.094382 / 0.043533 (0.050849) | 0.483000 / 0.255139 (0.227861) | 0.522693 / 0.283200 (0.239494) | 0.138804 / 0.141683 (-0.002879) | 1.719563 / 1.452155 (0.267409) | 1.853470 / 1.492716 (0.360753) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.235616 / 0.018006 (0.217610) | 0.483267 / 0.000490 (0.482777) | 0.008663 / 0.000200 (0.008463) | 0.000401 / 0.000054 (0.000347) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.033124 / 0.037411 (-0.004287) | 0.128821 / 0.014526 (0.114295) | 0.138910 / 0.176557 (-0.037647) | 0.213570 / 0.737135 (-0.523566) | 0.146646 / 0.296338 (-0.149693) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.479998 / 0.215209 (0.264789) | 4.772325 / 2.077655 (2.694670) | 2.228424 / 1.504120 (0.724304) | 2.000915 / 1.541195 (0.459721) | 2.105799 / 1.468490 (0.637309) | 0.824235 / 4.584777 (-3.760542) | 4.511902 / 3.745712 (0.766189) | 4.723073 / 5.269862 (-0.546789) | 2.333442 / 4.565676 (-2.232235) | 0.101161 / 0.424275 (-0.323114) | 0.014403 / 0.007607 (0.006796) | 0.596395 / 0.226044 (0.370351) | 5.961046 / 2.268929 (3.692117) | 2.746679 / 55.444624 (-52.697946) | 2.352085 / 6.876477 (-4.524392) | 2.609812 / 2.142072 (0.467740) | 0.996950 / 4.805227 (-3.808277) | 0.197923 / 6.500664 (-6.302741) | 0.075546 / 0.075469 (0.000077) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.529896 / 1.841788 (-0.311892) | 18.183887 / 8.074308 (10.109578) | 16.352332 / 10.191392 (6.160940) | 0.213504 / 0.680424 (-0.466920) | 0.020388 / 0.534201 (-0.513813) | 0.497832 / 0.579283 (-0.081451) | 0.495477 / 0.434364 (0.061113) | 0.585984 / 0.540337 (0.045647) | 0.688726 / 1.386936 (-0.698210) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008422 / 0.011353 (-0.002931) | 0.005876 / 0.011008 (-0.005132) | 0.089310 / 0.038508 (0.050802) | 0.039769 / 0.023109 (0.016660) | 0.425279 / 0.275898 (0.149381) | 0.470818 / 0.323480 (0.147338) | 0.006519 / 0.007986 (-0.001467) | 0.006276 / 0.004328 (0.001948) | 0.085753 / 0.004250 (0.081503) | 0.053867 / 0.037052 (0.016815) | 0.429193 / 0.258489 (0.170704) | 0.480278 / 0.293841 (0.186437) | 0.040657 / 0.128546 (-0.087889) | 0.014055 / 0.075646 (-0.061591) | 0.101422 / 0.419271 (-0.317849) | 0.053803 / 0.043533 (0.010271) | 0.428348 / 0.255139 (0.173209) | 0.452193 / 0.283200 (0.168994) | 0.124914 / 0.141683 (-0.016769) | 1.750122 / 1.452155 (0.297968) | 1.850875 / 1.492716 (0.358159) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.249958 / 0.018006 (0.231952) | 0.485183 / 0.000490 (0.484694) | 0.000472 / 0.000200 (0.000272) | 0.000069 / 0.000054 (0.000015) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.034563 / 0.037411 (-0.002848) | 0.135565 / 0.014526 (0.121039) | 0.143271 / 0.176557 (-0.033285) | 0.199080 / 0.737135 (-0.538056) | 0.149336 / 0.296338 (-0.147003) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.526170 / 0.215209 (0.310961) | 5.270960 / 2.077655 (3.193305) | 2.664585 / 1.504120 (1.160465) | 2.440027 / 1.541195 (0.898832) | 2.612764 / 1.468490 (1.144274) | 0.828965 / 4.584777 (-3.755812) | 4.769983 / 3.745712 (1.024271) | 2.441962 / 5.269862 (-2.827900) | 1.549032 / 4.565676 (-3.016644) | 0.100851 / 0.424275 (-0.323424) | 0.014425 / 0.007607 (0.006818) | 0.640908 / 0.226044 (0.414864) | 6.399041 / 2.268929 (4.130113) | 3.242424 / 55.444624 (-52.202200) | 2.836317 / 6.876477 (-4.040160) | 2.933010 / 2.142072 (0.790938) | 1.002277 / 4.805227 (-3.802950) | 0.201247 / 6.500664 (-6.299417) | 0.078777 / 0.075469 (0.003308) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.620415 / 1.841788 (-0.221373) | 19.153631 / 8.074308 (11.079323) | 16.744068 / 10.191392 (6.552676) | 0.167327 / 0.680424 (-0.513097) | 0.020186 / 0.534201 (-0.514015) | 0.503683 / 0.579283 (-0.075600) | 0.500051 / 0.434364 (0.065687) | 0.587188 / 0.540337 (0.046850) | 0.699975 / 1.386936 (-0.686961) |

</details>
</details>

![](https://cml.dev/watermark.png#291d7ffa695edb4b4e818c783b16d3466246cd56 "CML watermark")


This is probably ready, but likely conflicts with #5883. I'll wait for that PR to be merged and then rebase and merge this one.

<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008387 / 0.011353 (-0.002965) | 0.005824 / 0.011008 (-0.005184) | 0.117721 / 0.038508 (0.079213) | 0.040420 / 0.023109 (0.017311) | 0.404961 / 0.275898 (0.129063) | 0.426695 / 0.323480 (0.103215) | 0.006634 / 0.007986 (-0.001352) | 0.006033 / 0.004328 (0.001705) | 0.088652 / 0.004250 (0.084402) | 0.048075 / 0.037052 (0.011022) | 0.400683 / 0.258489 (0.142194) | 0.432489 / 0.293841 (0.138648) | 0.042065 / 0.128546 (-0.086482) | 0.014071 / 0.075646 (-0.061575) | 0.399398 / 0.419271 (-0.019873) | 0.066034 / 0.043533 (0.022501) | 0.400056 / 0.255139 (0.144918) | 0.421130 / 0.283200 (0.137930) | 0.119721 / 0.141683 (-0.021962) | 1.752166 / 1.452155 (0.300011) | 1.820161 / 1.492716 (0.327444) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.244264 / 0.018006 (0.226258) | 0.480882 / 0.000490 (0.480392) | 0.005604 / 0.000200 (0.005404) | 0.000175 / 0.000054 (0.000121) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.032397 / 0.037411 (-0.005015) | 0.131632 / 0.014526 (0.117106) | 0.139765 / 0.176557 (-0.036792) | 0.213135 / 0.737135 (-0.524000) | 0.147891 / 0.296338 (-0.148447) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.474534 / 0.215209 (0.259325) | 4.730424 / 2.077655 (2.652770) | 2.163706 / 1.504120 (0.659586) | 1.936051 / 1.541195 (0.394857) | 2.012185 / 1.468490 (0.543695) | 0.826583 / 4.584777 (-3.758194) | 4.921494 / 3.745712 (1.175782) | 2.431401 / 5.269862 (-2.838460) | 1.566020 / 4.565676 (-2.999656) | 0.101255 / 0.424275 (-0.323020) | 0.014553 / 0.007607 (0.006946) | 0.608301 / 0.226044 (0.382256) | 6.089801 / 2.268929 (3.820873) | 2.691986 / 55.444624 (-52.752638) | 2.296498 / 6.876477 (-4.579979) | 2.455388 / 2.142072 (0.313315) | 0.984342 / 4.805227 (-3.820885) | 0.200447 / 6.500664 (-6.300217) | 0.077602 / 0.075469 (0.002133) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.445067 / 1.841788 (-0.396721) | 18.588670 / 8.074308 (10.514362) | 16.950216 / 10.191392 (6.758824) | 0.169688 / 0.680424 (-0.510736) | 0.020544 / 0.534201 (-0.513657) | 0.508506 / 0.579283 (-0.070777) | 0.516218 / 0.434364 (0.081854) | 0.646072 / 0.540337 (0.105734) | 0.763227 / 1.386936 (-0.623709) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008816 / 0.011353 (-0.002537) | 0.006016 / 0.011008 (-0.004992) | 0.090946 / 0.038508 (0.052438) | 0.040189 / 0.023109 (0.017080) | 0.446723 / 0.275898 (0.170825) | 0.494633 / 0.323480 (0.171153) | 0.007206 / 0.007986 (-0.000779) | 0.004508 / 0.004328 (0.000180) | 0.088477 / 0.004250 (0.084226) | 0.055587 / 0.037052 (0.018535) | 0.445349 / 0.258489 (0.186860) | 0.504940 / 0.293841 (0.211099) | 0.041976 / 0.128546 (-0.086570) | 0.014296 / 0.075646 (-0.061351) | 0.102835 / 0.419271 (-0.316436) | 0.054786 / 0.043533 (0.011253) | 0.444789 / 0.255139 (0.189651) | 0.472306 / 0.283200 (0.189106) | 0.123365 / 0.141683 (-0.018318) | 1.725803 / 1.452155 (0.273648) | 1.832216 / 1.492716 (0.339500) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.252680 / 0.018006 (0.234674) | 0.476719 / 0.000490 (0.476229) | 0.000461 / 0.000200 (0.000261) | 0.000067 / 0.000054 (0.000013) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.035961 / 0.037411 (-0.001450) | 0.135399 / 0.014526 (0.120873) | 0.147549 / 0.176557 (-0.029007) | 0.207468 / 0.737135 (-0.529667) | 0.151591 / 0.296338 (-0.144747) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.528143 / 0.215209 (0.312934) | 5.270766 / 2.077655 (3.193111) | 2.675644 / 1.504120 (1.171524) | 2.472855 / 1.541195 (0.931660) | 2.636020 / 1.468490 (1.167530) | 0.841325 / 4.584777 (-3.743452) | 4.702290 / 3.745712 (0.956578) | 2.523537 / 5.269862 (-2.746325) | 1.595617 / 4.565676 (-2.970059) | 0.102095 / 0.424275 (-0.322180) | 0.014568 / 0.007607 (0.006961) | 0.652090 / 0.226044 (0.426046) | 6.503086 / 2.268929 (4.234158) | 3.277025 / 55.444624 (-52.167599) | 2.931264 / 6.876477 (-3.945213) | 3.021667 / 2.142072 (0.879594) | 1.002560 / 4.805227 (-3.802668) | 0.202621 / 6.500664 (-6.298043) | 0.080583 / 0.075469 (0.005114) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.639281 / 1.841788 (-0.202507) | 18.911529 / 8.074308 (10.837220) | 17.082795 / 10.191392 (6.891403) | 0.179456 / 0.680424 (-0.500968) | 0.021740 / 0.534201 (-0.512460) | 0.526426 / 0.579283 (-0.052857) | 0.535083 / 0.434364 (0.100719) | 0.583304 / 0.540337 (0.042967) | 0.696733 / 1.386936 (-0.690203) |

</details>
</details>

![](https://cml.dev/watermark.png#757f19283f22eeb3e9aedefd82abc0aa2235f797 "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.006823 / 0.011353 (-0.004530) | 0.004847 / 0.011008 (-0.006161) | 0.096038 / 0.038508 (0.057530) | 0.033037 / 0.023109 (0.009928) | 0.298379 / 0.275898 (0.022481) | 0.333319 / 0.323480 (0.009839) | 0.005343 / 0.007986 (-0.002643) | 0.003863 / 0.004328 (-0.000465) | 0.072928 / 0.004250 (0.068678) | 0.040898 / 0.037052 (0.003846) | 0.303116 / 0.258489 (0.044627) | 0.334021 / 0.293841 (0.040181) | 0.034780 / 0.128546 (-0.093767) | 0.011978 / 0.075646 (-0.063668) | 0.331642 / 0.419271 (-0.087629) | 0.052729 / 0.043533 (0.009196) | 0.298586 / 0.255139 (0.043447) | 0.319296 / 0.283200 (0.036097) | 0.097711 / 0.141683 (-0.043972) | 1.416899 / 1.452155 (-0.035256) | 1.546008 / 1.492716 (0.053292) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.234303 / 0.018006 (0.216296) | 0.492767 / 0.000490 (0.492278) | 0.004935 / 0.000200 (0.004736) | 0.000106 / 0.000054 (0.000051) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.030617 / 0.037411 (-0.006795) | 0.121203 / 0.014526 (0.106677) | 0.126677 / 0.176557 (-0.049879) | 0.186379 / 0.737135 (-0.550756) | 0.129849 / 0.296338 (-0.166490) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.416324 / 0.215209 (0.201115) | 4.135563 / 2.077655 (2.057908) | 1.976182 / 1.504120 (0.472062) | 1.807611 / 1.541195 (0.266416) | 1.886282 / 1.468490 (0.417792) | 0.713006 / 4.584777 (-3.871771) | 3.899205 / 3.745712 (0.153493) | 2.283427 / 5.269862 (-2.986435) | 1.543088 / 4.565676 (-3.022589) | 0.086189 / 0.424275 (-0.338087) | 0.012908 / 0.007607 (0.005301) | 0.516156 / 0.226044 (0.290112) | 5.144199 / 2.268929 (2.875271) | 2.460142 / 55.444624 (-52.984482) | 2.209054 / 6.876477 (-4.667423) | 2.325277 / 2.142072 (0.183204) | 0.849890 / 4.805227 (-3.955337) | 0.173687 / 6.500664 (-6.326977) | 0.070178 / 0.075469 (-0.005291) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.241790 / 1.841788 (-0.599997) | 16.047257 / 8.074308 (7.972949) | 15.774146 / 10.191392 (5.582754) | 0.145871 / 0.680424 (-0.534553) | 0.018106 / 0.534201 (-0.516095) | 0.433642 / 0.579283 (-0.145641) | 0.425311 / 0.434364 (-0.009053) | 0.533963 / 0.540337 (-0.006375) | 0.638786 / 1.386936 (-0.748151) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.007242 / 0.011353 (-0.004111) | 0.005599 / 0.011008 (-0.005410) | 0.073443 / 0.038508 (0.034935) | 0.033764 / 0.023109 (0.010655) | 0.365990 / 0.275898 (0.090092) | 0.392943 / 0.323480 (0.069463) | 0.005987 / 0.007986 (-0.001999) | 0.004312 / 0.004328 (-0.000016) | 0.072831 / 0.004250 (0.068580) | 0.048854 / 0.037052 (0.011802) | 0.362477 / 0.258489 (0.103988) | 0.399993 / 0.293841 (0.106152) | 0.035602 / 0.128546 (-0.092944) | 0.012445 / 0.075646 (-0.063202) | 0.085768 / 0.419271 (-0.333504) | 0.048544 / 0.043533 (0.005011) | 0.362246 / 0.255139 (0.107107) | 0.388753 / 0.283200 (0.105554) | 0.109829 / 0.141683 (-0.031854) | 1.546881 / 1.452155 (0.094726) | 1.619454 / 1.492716 (0.126737) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.189926 / 0.018006 (0.171920) | 0.447936 / 0.000490 (0.447446) | 0.002354 / 0.000200 (0.002155) | 0.000090 / 0.000054 (0.000035) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.031740 / 0.037411 (-0.005671) | 0.122595 / 0.014526 (0.108069) | 0.128389 / 0.176557 (-0.048168) | 0.180570 / 0.737135 (-0.556566) | 0.132939 / 0.296338 (-0.163399) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.425073 / 0.215209 (0.209863) | 4.238964 / 2.077655 (2.161309) | 2.095116 / 1.504120 (0.590996) | 1.913925 / 1.541195 (0.372730) | 2.024669 / 1.468490 (0.556179) | 0.699172 / 4.584777 (-3.885605) | 3.845807 / 3.745712 (0.100094) | 2.167502 / 5.269862 (-3.102360) | 1.375267 / 4.565676 (-3.190410) | 0.086739 / 0.424275 (-0.337536) | 0.012198 / 0.007607 (0.004591) | 0.525975 / 0.226044 (0.299931) | 5.249449 / 2.268929 (2.980521) | 2.550565 / 55.444624 (-52.894060) | 2.257557 / 6.876477 (-4.618920) | 2.298936 / 2.142072 (0.156863) | 0.850295 / 4.805227 (-3.954932) | 0.170506 / 6.500664 (-6.330158) | 0.065659 / 0.075469 (-0.009810) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.330556 / 1.841788 (-0.511231) | 16.920203 / 8.074308 (8.845894) | 15.966739 / 10.191392 (5.775347) | 0.164000 / 0.680424 (-0.516424) | 0.018211 / 0.534201 (-0.515990) | 0.436253 / 0.579283 (-0.143030) | 0.449666 / 0.434364 (0.015302) | 0.522287 / 0.540337 (-0.018050) | 0.615944 / 1.386936 (-0.770992) |

</details>
</details>

![](https://cml.dev/watermark.png#824f96c11a02b3817d6b1bf4dfed0abab27777f0 "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.007273 / 0.011353 (-0.004080) | 0.005198 / 0.011008 (-0.005810) | 0.114362 / 0.038508 (0.075854) | 0.031113 / 0.023109 (0.008003) | 0.378568 / 0.275898 (0.102670) | 0.441695 / 0.323480 (0.118215) | 0.006037 / 0.007986 (-0.001949) | 0.005102 / 0.004328 (0.000774) | 0.098682 / 0.004250 (0.094432) | 0.042797 / 0.037052 (0.005745) | 0.360028 / 0.258489 (0.101539) | 0.435757 / 0.293841 (0.141916) | 0.041438 / 0.128546 (-0.087109) | 0.013728 / 0.075646 (-0.061918) | 0.376154 / 0.419271 (-0.043117) | 0.075324 / 0.043533 (0.031791) | 0.357221 / 0.255139 (0.102082) | 0.416378 / 0.283200 (0.133178) | 0.110707 / 0.141683 (-0.030975) | 1.603215 / 1.452155 (0.151061) | 1.736843 / 1.492716 (0.244127) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.249479 / 0.018006 (0.231473) | 0.513205 / 0.000490 (0.512715) | 0.003856 / 0.000200 (0.003656) | 0.000100 / 0.000054 (0.000045) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.027750 / 0.037411 (-0.009661) | 0.105437 / 0.014526 (0.090911) | 0.115903 / 0.176557 (-0.060653) | 0.179662 / 0.737135 (-0.557474) | 0.116305 / 0.296338 (-0.180033) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.551681 / 0.215209 (0.336472) | 5.544590 / 2.077655 (3.466935) | 2.193933 / 1.504120 (0.689813) | 1.898395 / 1.541195 (0.357201) | 1.877288 / 1.468490 (0.408798) | 0.858097 / 4.584777 (-3.726680) | 4.920982 / 3.745712 (1.175270) | 2.478220 / 5.269862 (-2.791641) | 1.779608 / 4.565676 (-2.786069) | 0.101321 / 0.424275 (-0.322954) | 0.012627 / 0.007607 (0.005020) | 0.674865 / 0.226044 (0.448820) | 6.808224 / 2.268929 (4.539295) | 2.822466 / 55.444624 (-52.622159) | 2.170379 / 6.876477 (-4.706098) | 2.224278 / 2.142072 (0.082205) | 1.032763 / 4.805227 (-3.772464) | 0.198851 / 6.500664 (-6.301813) | 0.069249 / 0.075469 (-0.006220) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.425987 / 1.841788 (-0.415801) | 16.212942 / 8.074308 (8.138634) | 18.945770 / 10.191392 (8.754378) | 0.192901 / 0.680424 (-0.487522) | 0.025343 / 0.534201 (-0.508858) | 0.465441 / 0.579283 (-0.113842) | 0.540966 / 0.434364 (0.106602) | 0.576736 / 0.540337 (0.036399) | 0.675717 / 1.386936 (-0.711219) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.007426 / 0.011353 (-0.003927) | 0.005023 / 0.011008 (-0.005985) | 0.085083 / 0.038508 (0.046575) | 0.030559 / 0.023109 (0.007449) | 0.398461 / 0.275898 (0.122563) | 0.418998 / 0.323480 (0.095518) | 0.006697 / 0.007986 (-0.001288) | 0.004665 / 0.004328 (0.000337) | 0.087724 / 0.004250 (0.083473) | 0.045799 / 0.037052 (0.008747) | 0.395165 / 0.258489 (0.136676) | 0.430172 / 0.293841 (0.136331) | 0.040486 / 0.128546 (-0.088060) | 0.014237 / 0.075646 (-0.061409) | 0.099429 / 0.419271 (-0.319843) | 0.056006 / 0.043533 (0.012473) | 0.389046 / 0.255139 (0.133907) | 0.419559 / 0.283200 (0.136359) | 0.108550 / 0.141683 (-0.033132) | 1.614052 / 1.452155 (0.161897) | 1.677785 / 1.492716 (0.185069) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.202178 / 0.018006 (0.184172) | 0.486365 / 0.000490 (0.485875) | 0.003844 / 0.000200 (0.003644) | 0.000112 / 0.000054 (0.000058) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.027963 / 0.037411 (-0.009449) | 0.110399 / 0.014526 (0.095873) | 0.122266 / 0.176557 (-0.054291) | 0.178551 / 0.737135 (-0.558585) | 0.129259 / 0.296338 (-0.167080) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.604178 / 0.215209 (0.388969) | 6.135943 / 2.077655 (4.058288) | 2.547576 / 1.504120 (1.043456) | 2.262470 / 1.541195 (0.721276) | 2.275402 / 1.468490 (0.806912) | 0.878804 / 4.584777 (-3.705972) | 5.152200 / 3.745712 (1.406488) | 2.553715 / 5.269862 (-2.716147) | 1.580959 / 4.565676 (-2.984717) | 0.107895 / 0.424275 (-0.316380) | 0.012751 / 0.007607 (0.005143) | 0.770678 / 0.226044 (0.544633) | 7.744303 / 2.268929 (5.475374) | 3.342037 / 55.444624 (-52.102588) | 2.756848 / 6.876477 (-4.119629) | 2.739357 / 2.142072 (0.597285) | 1.086330 / 4.805227 (-3.718897) | 0.230983 / 6.500664 (-6.269681) | 0.073771 / 0.075469 (-0.001698) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.493441 / 1.841788 (-0.348347) | 16.621611 / 8.074308 (8.547303) | 19.081000 / 10.191392 (8.889608) | 0.215623 / 0.680424 (-0.464801) | 0.025660 / 0.534201 (-0.508541) | 0.446490 / 0.579283 (-0.132793) | 0.560078 / 0.434364 (0.125714) | 0.527231 / 0.540337 (-0.013106) | 0.636551 / 1.386936 (-0.750385) |

</details>
</details>

![](https://cml.dev/watermark.png#b899ea45c0a7e724ceb5f43c3a8b9fdb081fa67a "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008266 / 0.011353 (-0.003087) | 0.005082 / 0.011008 (-0.005927) | 0.119858 / 0.038508 (0.081350) | 0.032907 / 0.023109 (0.009798) | 0.362816 / 0.275898 (0.086918) | 0.403684 / 0.323480 (0.080204) | 0.006296 / 0.007986 (-0.001690) | 0.006220 / 0.004328 (0.001891) | 0.095609 / 0.004250 (0.091359) | 0.048734 / 0.037052 (0.011682) | 0.385724 / 0.258489 (0.127235) | 0.424315 / 0.293841 (0.130475) | 0.042344 / 0.128546 (-0.086202) | 0.016147 / 0.075646 (-0.059500) | 0.409661 / 0.419271 (-0.009610) | 0.057900 / 0.043533 (0.014367) | 0.387013 / 0.255139 (0.131874) | 0.388901 / 0.283200 (0.105702) | 0.103920 / 0.141683 (-0.037762) | 1.732730 / 1.452155 (0.280575) | 1.863912 / 1.492716 (0.371196) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.237406 / 0.018006 (0.219400) | 0.514398 / 0.000490 (0.513909) | 0.005941 / 0.000200 (0.005741) | 0.000109 / 0.000054 (0.000054) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.027524 / 0.037411 (-0.009888) | 0.116498 / 0.014526 (0.101972) | 0.129034 / 0.176557 (-0.047522) | 0.218272 / 0.737135 (-0.518864) | 0.148389 / 0.296338 (-0.147950) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.604555 / 0.215209 (0.389346) | 5.921576 / 2.077655 (3.843921) | 2.410483 / 1.504120 (0.906363) | 2.220286 / 1.541195 (0.679092) | 2.138880 / 1.468490 (0.670390) | 0.934962 / 4.584777 (-3.649815) | 5.808855 / 3.745712 (2.063143) | 4.881554 / 5.269862 (-0.388308) | 2.536408 / 4.565676 (-2.029268) | 0.124260 / 0.424275 (-0.300015) | 0.017798 / 0.007607 (0.010190) | 0.778991 / 0.226044 (0.552947) | 7.899262 / 2.268929 (5.630333) | 3.208667 / 55.444624 (-52.235957) | 2.631182 / 6.876477 (-4.245295) | 2.676199 / 2.142072 (0.534127) | 1.165516 / 4.805227 (-3.639711) | 0.228751 / 6.500664 (-6.271913) | 0.081378 / 0.075469 (0.005909) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.522156 / 1.841788 (-0.319632) | 17.975381 / 8.074308 (9.901073) | 18.918882 / 10.191392 (8.727490) | 0.223984 / 0.680424 (-0.456440) | 0.025171 / 0.534201 (-0.509030) | 0.467894 / 0.579283 (-0.111389) | 0.559501 / 0.434364 (0.125137) | 0.550392 / 0.540337 (0.010055) | 0.696923 / 1.386936 (-0.690013) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008577 / 0.011353 (-0.002775) | 0.006735 / 0.011008 (-0.004273) | 0.095108 / 0.038508 (0.056600) | 0.035059 / 0.023109 (0.011950) | 0.448576 / 0.275898 (0.172677) | 0.492049 / 0.323480 (0.168569) | 0.006600 / 0.007986 (-0.001385) | 0.004760 / 0.004328 (0.000431) | 0.094670 / 0.004250 (0.090419) | 0.052543 / 0.037052 (0.015491) | 0.458927 / 0.258489 (0.200438) | 0.511522 / 0.293841 (0.217681) | 0.046046 / 0.128546 (-0.082500) | 0.015227 / 0.075646 (-0.060419) | 0.114585 / 0.419271 (-0.304686) | 0.057569 / 0.043533 (0.014036) | 0.441989 / 0.255139 (0.186850) | 0.487001 / 0.283200 (0.203801) | 0.115688 / 0.141683 (-0.025995) | 1.777366 / 1.452155 (0.325211) | 1.906216 / 1.492716 (0.413499) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.224880 / 0.018006 (0.206874) | 0.504153 / 0.000490 (0.503664) | 0.001143 / 0.000200 (0.000943) | 0.000111 / 0.000054 (0.000056) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.033618 / 0.037411 (-0.003793) | 0.127396 / 0.014526 (0.112870) | 0.135648 / 0.176557 (-0.040909) | 0.193140 / 0.737135 (-0.543995) | 0.142129 / 0.296338 (-0.154209) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.692845 / 0.215209 (0.477636) | 6.804897 / 2.077655 (4.727242) | 2.851041 / 1.504120 (1.346921) | 2.480698 / 1.541195 (0.939504) | 2.488619 / 1.468490 (1.020129) | 0.970439 / 4.584777 (-3.614338) | 5.466059 / 3.745712 (1.720347) | 2.790261 / 5.269862 (-2.479601) | 1.727638 / 4.565676 (-2.838039) | 0.116345 / 0.424275 (-0.307930) | 0.014348 / 0.007607 (0.006740) | 0.845510 / 0.226044 (0.619465) | 8.397198 / 2.268929 (6.128270) | 3.591998 / 55.444624 (-51.852626) | 2.858339 / 6.876477 (-4.018137) | 2.905075 / 2.142072 (0.763003) | 1.193569 / 4.805227 (-3.611658) | 0.243091 / 6.500664 (-6.257573) | 0.082198 / 0.075469 (0.006729) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.610327 / 1.841788 (-0.231461) | 17.191414 / 8.074308 (9.117106) | 20.176518 / 10.191392 (9.985126) | 0.246574 / 0.680424 (-0.433850) | 0.024343 / 0.534201 (-0.509858) | 0.482091 / 0.579283 (-0.097192) | 0.585241 / 0.434364 (0.150877) | 0.558833 / 0.540337 (0.018496) | 0.654811 / 1.386936 (-0.732125) |

</details>
</details>

![](https://cml.dev/watermark.png#81761dbfa738354a9c50309313dfe90bea26d872 "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.006353 / 0.011353 (-0.004999) | 0.004393 / 0.011008 (-0.006616) | 0.098751 / 0.038508 (0.060242) | 0.029090 / 0.023109 (0.005981) | 0.304169 / 0.275898 (0.028271) | 0.339879 / 0.323480 (0.016399) | 0.005577 / 0.007986 (-0.002408) | 0.003516 / 0.004328 (-0.000813) | 0.077347 / 0.004250 (0.073097) | 0.041935 / 0.037052 (0.004882) | 0.305865 / 0.258489 (0.047376) | 0.357063 / 0.293841 (0.063222) | 0.025245 / 0.128546 (-0.103301) | 0.008753 / 0.075646 (-0.066893) | 0.316734 / 0.419271 (-0.102538) | 0.043464 / 0.043533 (-0.000069) | 0.300944 / 0.255139 (0.045805) | 0.330091 / 0.283200 (0.046891) | 0.088593 / 0.141683 (-0.053090) | 1.588958 / 1.452155 (0.136803) | 1.641376 / 1.492716 (0.148660) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.220290 / 0.018006 (0.202284) | 0.445430 / 0.000490 (0.444940) | 0.004800 / 0.000200 (0.004600) | 0.000075 / 0.000054 (0.000020) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.023828 / 0.037411 (-0.013583) | 0.103446 / 0.014526 (0.088920) | 0.110668 / 0.176557 (-0.065889) | 0.169604 / 0.737135 (-0.567531) | 0.114818 / 0.296338 (-0.181520) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.416951 / 0.215209 (0.201742) | 4.138917 / 2.077655 (2.061263) | 1.891265 / 1.504120 (0.387145) | 1.687068 / 1.541195 (0.145873) | 1.726618 / 1.468490 (0.258128) | 0.546977 / 4.584777 (-4.037800) | 3.536153 / 3.745712 (-0.209560) | 1.795206 / 5.269862 (-3.474656) | 1.019845 / 4.565676 (-3.545831) | 0.067040 / 0.424275 (-0.357235) | 0.012038 / 0.007607 (0.004431) | 0.520583 / 0.226044 (0.294539) | 5.211520 / 2.268929 (2.942591) | 2.336136 / 55.444624 (-53.108488) | 2.011262 / 6.876477 (-4.865215) | 2.137311 / 2.142072 (-0.004762) | 0.654779 / 4.805227 (-4.150448) | 0.134555 / 6.500664 (-6.366109) | 0.066427 / 0.075469 (-0.009042) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.240187 / 1.841788 (-0.601600) | 14.104063 / 8.074308 (6.029755) | 13.369572 / 10.191392 (3.178180) | 0.147891 / 0.680424 (-0.532533) | 0.016993 / 0.534201 (-0.517208) | 0.364863 / 0.579283 (-0.214420) | 0.398684 / 0.434364 (-0.035680) | 0.430524 / 0.540337 (-0.109813) | 0.520920 / 1.386936 (-0.866016) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.006845 / 0.011353 (-0.004508) | 0.004420 / 0.011008 (-0.006588) | 0.078334 / 0.038508 (0.039825) | 0.030566 / 0.023109 (0.007457) | 0.409568 / 0.275898 (0.133670) | 0.458389 / 0.323480 (0.134910) | 0.005739 / 0.007986 (-0.002247) | 0.005222 / 0.004328 (0.000893) | 0.076066 / 0.004250 (0.071816) | 0.049239 / 0.037052 (0.012187) | 0.409841 / 0.258489 (0.151352) | 0.472250 / 0.293841 (0.178409) | 0.025463 / 0.128546 (-0.103084) | 0.008738 / 0.075646 (-0.066909) | 0.083114 / 0.419271 (-0.336157) | 0.041233 / 0.043533 (-0.002300) | 0.407158 / 0.255139 (0.152019) | 0.438724 / 0.283200 (0.155524) | 0.097974 / 0.141683 (-0.043709) | 1.536514 / 1.452155 (0.084360) | 1.636704 / 1.492716 (0.143987) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.240589 / 0.018006 (0.222583) | 0.440328 / 0.000490 (0.439838) | 0.000937 / 0.000200 (0.000737) | 0.000076 / 0.000054 (0.000021) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.027559 / 0.037411 (-0.009853) | 0.109930 / 0.014526 (0.095405) | 0.113366 / 0.176557 (-0.063190) | 0.166849 / 0.737135 (-0.570286) | 0.118872 / 0.296338 (-0.177467) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.474120 / 0.215209 (0.258911) | 4.739222 / 2.077655 (2.661567) | 2.484386 / 1.504120 (0.980266) | 2.281937 / 1.541195 (0.740742) | 2.362974 / 1.468490 (0.894484) | 0.549897 / 4.584777 (-4.034879) | 3.425540 / 3.745712 (-0.320172) | 1.765810 / 5.269862 (-3.504051) | 1.008277 / 4.565676 (-3.557400) | 0.067288 / 0.424275 (-0.356987) | 0.011954 / 0.007607 (0.004347) | 0.577216 / 0.226044 (0.351172) | 5.790659 / 2.268929 (3.521731) | 2.946732 / 55.444624 (-52.497892) | 2.608835 / 6.876477 (-4.267641) | 2.642987 / 2.142072 (0.500915) | 0.652798 / 4.805227 (-4.152429) | 0.135909 / 6.500664 (-6.364755) | 0.068480 / 0.075469 (-0.006989) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.353550 / 1.841788 (-0.488237) | 14.732084 / 8.074308 (6.657775) | 14.439174 / 10.191392 (4.247782) | 0.131445 / 0.680424 (-0.548979) | 0.016608 / 0.534201 (-0.517593) | 0.368103 / 0.579283 (-0.211180) | 0.393918 / 0.434364 (-0.040446) | 0.423562 / 0.540337 (-0.116776) | 0.515041 / 1.386936 (-0.871895) |

</details>
</details>

![](https://cml.dev/watermark.png#8907bdb23f78545303eb3bb0561e33ec6787f96c "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.006414 / 0.011353 (-0.004938) | 0.004704 / 0.011008 (-0.006305) | 0.096012 / 0.038508 (0.057504) | 0.032910 / 0.023109 (0.009800) | 0.290676 / 0.275898 (0.014778) | 0.319646 / 0.323480 (-0.003834) | 0.005806 / 0.007986 (-0.002180) | 0.004008 / 0.004328 (-0.000320) | 0.073982 / 0.004250 (0.069731) | 0.048985 / 0.037052 (0.011933) | 0.299498 / 0.258489 (0.041009) | 0.338118 / 0.293841 (0.044277) | 0.027680 / 0.128546 (-0.100866) | 0.009051 / 0.075646 (-0.066595) | 0.325051 / 0.419271 (-0.094221) | 0.051011 / 0.043533 (0.007478) | 0.292249 / 0.255139 (0.037110) | 0.315733 / 0.283200 (0.032533) | 0.100327 / 0.141683 (-0.041356) | 1.481862 / 1.452155 (0.029707) | 1.544884 / 1.492716 (0.052168) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.289610 / 0.018006 (0.271603) | 0.510164 / 0.000490 (0.509675) | 0.004726 / 0.000200 (0.004526) | 0.000090 / 0.000054 (0.000036) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.027617 / 0.037411 (-0.009794) | 0.107593 / 0.014526 (0.093068) | 0.122783 / 0.176557 (-0.053774) | 0.181086 / 0.737135 (-0.556049) | 0.128030 / 0.296338 (-0.168308) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.403571 / 0.215209 (0.188362) | 4.002881 / 2.077655 (1.925227) | 1.805550 / 1.504120 (0.301430) | 1.619165 / 1.541195 (0.077971) | 1.606536 / 1.468490 (0.138046) | 0.518917 / 4.584777 (-4.065860) | 3.731498 / 3.745712 (-0.014214) | 3.206645 / 5.269862 (-2.063217) | 1.641615 / 4.565676 (-2.924062) | 0.065100 / 0.424275 (-0.359175) | 0.011396 / 0.007607 (0.003789) | 0.500597 / 0.226044 (0.274553) | 4.992293 / 2.268929 (2.723364) | 2.278726 / 55.444624 (-53.165898) | 1.960823 / 6.876477 (-4.915654) | 2.038684 / 2.142072 (-0.103388) | 0.640910 / 4.805227 (-4.164318) | 0.140597 / 6.500664 (-6.360067) | 0.062114 / 0.075469 (-0.013355) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.167366 / 1.841788 (-0.674422) | 14.748193 / 8.074308 (6.673884) | 13.592381 / 10.191392 (3.400989) | 0.165341 / 0.680424 (-0.515083) | 0.017360 / 0.534201 (-0.516841) | 0.393448 / 0.579283 (-0.185836) | 0.422951 / 0.434364 (-0.011413) | 0.460491 / 0.540337 (-0.079847) | 0.558238 / 1.386936 (-0.828698) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.006373 / 0.011353 (-0.004980) | 0.004587 / 0.011008 (-0.006421) | 0.076421 / 0.038508 (0.037913) | 0.032162 / 0.023109 (0.009052) | 0.385531 / 0.275898 (0.109633) | 0.410424 / 0.323480 (0.086944) | 0.006154 / 0.007986 (-0.001832) | 0.005533 / 0.004328 (0.001205) | 0.077035 / 0.004250 (0.072784) | 0.051571 / 0.037052 (0.014519) | 0.393283 / 0.258489 (0.134794) | 0.433756 / 0.293841 (0.139915) | 0.028381 / 0.128546 (-0.100165) | 0.009034 / 0.075646 (-0.066613) | 0.083836 / 0.419271 (-0.335435) | 0.048246 / 0.043533 (0.004713) | 0.385437 / 0.255139 (0.130298) | 0.394187 / 0.283200 (0.110987) | 0.105453 / 0.141683 (-0.036230) | 1.459173 / 1.452155 (0.007018) | 1.575083 / 1.492716 (0.082367) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.320324 / 0.018006 (0.302318) | 0.502945 / 0.000490 (0.502455) | 0.004470 / 0.000200 (0.004270) | 0.000107 / 0.000054 (0.000053) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.028118 / 0.037411 (-0.009293) | 0.111430 / 0.014526 (0.096904) | 0.123141 / 0.176557 (-0.053415) | 0.175215 / 0.737135 (-0.561920) | 0.126429 / 0.296338 (-0.169909) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.433407 / 0.215209 (0.218198) | 4.329945 / 2.077655 (2.252291) | 2.096822 / 1.504120 (0.592702) | 1.908173 / 1.541195 (0.366978) | 1.967167 / 1.468490 (0.498676) | 0.529207 / 4.584777 (-4.055570) | 3.798424 / 3.745712 (0.052712) | 3.050716 / 5.269862 (-2.219146) | 1.445009 / 4.565676 (-3.120668) | 0.066467 / 0.424275 (-0.357809) | 0.011698 / 0.007607 (0.004090) | 0.528660 / 0.226044 (0.302615) | 5.282069 / 2.268929 (3.013141) | 2.535501 / 55.444624 (-52.909124) | 2.202856 / 6.876477 (-4.673621) | 2.293225 / 2.142072 (0.151153) | 0.640216 / 4.805227 (-4.165011) | 0.140884 / 6.500664 (-6.359780) | 0.064231 / 0.075469 (-0.011238) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.292129 / 1.841788 (-0.549659) | 15.371370 / 8.074308 (7.297062) | 15.114854 / 10.191392 (4.923462) | 0.176870 / 0.680424 (-0.503554) | 0.017380 / 0.534201 (-0.516821) | 0.398156 / 0.579283 (-0.181127) | 0.442277 / 0.434364 (0.007913) | 0.467093 / 0.540337 (-0.073244) | 0.561599 / 1.386936 (-0.825337) |

</details>
</details>

![](https://cml.dev/watermark.png#323747a5ff7d9b204ea3c4989d658af7102f7bbd "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.009360 / 0.011353 (-0.001993) | 0.006297 / 0.011008 (-0.004712) | 0.133131 / 0.038508 (0.094623) | 0.040261 / 0.023109 (0.017152) | 0.419101 / 0.275898 (0.143203) | 0.453087 / 0.323480 (0.129607) | 0.007718 / 0.007986 (-0.000268) | 0.005698 / 0.004328 (0.001369) | 0.102261 / 0.004250 (0.098010) | 0.055147 / 0.037052 (0.018095) | 0.428355 / 0.258489 (0.169866) | 0.505241 / 0.293841 (0.211400) | 0.046745 / 0.128546 (-0.081802) | 0.015559 / 0.075646 (-0.060088) | 0.441775 / 0.419271 (0.022503) | 0.070165 / 0.043533 (0.026632) | 0.421957 / 0.255139 (0.166818) | 0.445156 / 0.283200 (0.161957) | 0.126321 / 0.141683 (-0.015362) | 1.900486 / 1.452155 (0.448331) | 2.088630 / 1.492716 (0.595913) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.260244 / 0.018006 (0.242237) | 0.606317 / 0.000490 (0.605828) | 0.006827 / 0.000200 (0.006627) | 0.000117 / 0.000054 (0.000063) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.031958 / 0.037411 (-0.005453) | 0.139362 / 0.014526 (0.124836) | 0.148748 / 0.176557 (-0.027809) | 0.226269 / 0.737135 (-0.510866) | 0.161145 / 0.296338 (-0.135194) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.666287 / 0.215209 (0.451078) | 6.588707 / 2.077655 (4.511053) | 2.736155 / 1.504120 (1.232035) | 2.329601 / 1.541195 (0.788406) | 2.324991 / 1.468490 (0.856501) | 0.943608 / 4.584777 (-3.641169) | 6.051653 / 3.745712 (2.305941) | 2.929150 / 5.269862 (-2.340711) | 1.804461 / 4.565676 (-2.761216) | 0.113302 / 0.424275 (-0.310973) | 0.015245 / 0.007607 (0.007638) | 0.827029 / 0.226044 (0.600984) | 8.211536 / 2.268929 (5.942608) | 3.445231 / 55.444624 (-51.999393) | 2.756728 / 6.876477 (-4.119748) | 2.904039 / 2.142072 (0.761966) | 1.162339 / 4.805227 (-3.642888) | 0.231168 / 6.500664 (-6.269496) | 0.089038 / 0.075469 (0.013569) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.640619 / 1.841788 (-0.201169) | 20.034157 / 8.074308 (11.959849) | 22.346006 / 10.191392 (12.154614) | 0.255300 / 0.680424 (-0.425124) | 0.031452 / 0.534201 (-0.502749) | 0.563290 / 0.579283 (-0.015993) | 0.653556 / 0.434364 (0.219192) | 0.687663 / 0.540337 (0.147326) | 0.816432 / 1.386936 (-0.570504) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.010340 / 0.011353 (-0.001013) | 0.006245 / 0.011008 (-0.004764) | 0.128012 / 0.038508 (0.089504) | 0.041799 / 0.023109 (0.018690) | 0.533340 / 0.275898 (0.257442) | 0.592243 / 0.323480 (0.268763) | 0.009256 / 0.007986 (0.001271) | 0.005310 / 0.004328 (0.000982) | 0.110973 / 0.004250 (0.106722) | 0.065465 / 0.037052 (0.028412) | 0.533845 / 0.258489 (0.275356) | 0.602190 / 0.293841 (0.308349) | 0.060245 / 0.128546 (-0.068301) | 0.016954 / 0.075646 (-0.058693) | 0.119727 / 0.419271 (-0.299545) | 0.064628 / 0.043533 (0.021095) | 0.558229 / 0.255139 (0.303090) | 0.563696 / 0.283200 (0.280496) | 0.137225 / 0.141683 (-0.004458) | 2.038605 / 1.452155 (0.586451) | 2.158655 / 1.492716 (0.665939) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.327067 / 0.018006 (0.309061) | 0.628812 / 0.000490 (0.628323) | 0.010259 / 0.000200 (0.010059) | 0.000123 / 0.000054 (0.000069) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.037023 / 0.037411 (-0.000388) | 0.142462 / 0.014526 (0.127936) | 0.158165 / 0.176557 (-0.018392) | 0.220808 / 0.737135 (-0.516328) | 0.163608 / 0.296338 (-0.132731) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.776119 / 0.215209 (0.560910) | 7.813044 / 2.077655 (5.735389) | 3.610901 / 1.504120 (2.106781) | 3.195144 / 1.541195 (1.653950) | 3.218245 / 1.468490 (1.749755) | 1.092732 / 4.584777 (-3.492045) | 5.965526 / 3.745712 (2.219813) | 2.914683 / 5.269862 (-2.355179) | 1.848397 / 4.565676 (-2.717280) | 0.114436 / 0.424275 (-0.309839) | 0.014794 / 0.007607 (0.007187) | 0.887141 / 0.226044 (0.661096) | 9.009743 / 2.268929 (6.740815) | 4.180143 / 55.444624 (-51.264481) | 3.452194 / 6.876477 (-3.424283) | 3.493520 / 2.142072 (1.351448) | 1.233327 / 4.805227 (-3.571900) | 0.235390 / 6.500664 (-6.265274) | 0.099544 / 0.075469 (0.024075) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.853482 / 1.841788 (0.011694) | 20.071177 / 8.074308 (11.996869) | 24.507618 / 10.191392 (14.316226) | 0.260164 / 0.680424 (-0.420260) | 0.028433 / 0.534201 (-0.505768) | 0.549181 / 0.579283 (-0.030102) | 0.650069 / 0.434364 (0.215705) | 0.629541 / 0.540337 (0.089203) | 0.808932 / 1.386936 (-0.578004) |

</details>
</details>

![](https://cml.dev/watermark.png#f39ba76af62c8037de3f464e87cbb095f8729062 "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.009537 / 0.011353 (-0.001816) | 0.006036 / 0.011008 (-0.004972) | 0.141210 / 0.038508 (0.102701) | 0.037493 / 0.023109 (0.014384) | 0.404285 / 0.275898 (0.128386) | 0.458906 / 0.323480 (0.135427) | 0.007224 / 0.007986 (-0.000761) | 0.005148 / 0.004328 (0.000819) | 0.103889 / 0.004250 (0.099639) | 0.048877 / 0.037052 (0.011824) | 0.413220 / 0.258489 (0.154731) | 0.458153 / 0.293841 (0.164312) | 0.046008 / 0.128546 (-0.082538) | 0.015116 / 0.075646 (-0.060531) | 0.439836 / 0.419271 (0.020565) | 0.067527 / 0.043533 (0.023994) | 0.435794 / 0.255139 (0.180656) | 0.451687 / 0.283200 (0.168487) | 0.121274 / 0.141683 (-0.020409) | 1.950199 / 1.452155 (0.498044) | 2.035589 / 1.492716 (0.542873) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.247056 / 0.018006 (0.229050) | 0.550348 / 0.000490 (0.549858) | 0.005504 / 0.000200 (0.005305) | 0.000116 / 0.000054 (0.000061) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.032171 / 0.037411 (-0.005240) | 0.135983 / 0.014526 (0.121457) | 0.149587 / 0.176557 (-0.026970) | 0.233414 / 0.737135 (-0.503722) | 0.152598 / 0.296338 (-0.143740) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.634813 / 0.215209 (0.419604) | 6.453619 / 2.077655 (4.375964) | 2.582070 / 1.504120 (1.077951) | 2.214292 / 1.541195 (0.673097) | 2.220012 / 1.468490 (0.751522) | 0.987374 / 4.584777 (-3.597403) | 5.543760 / 3.745712 (1.798047) | 2.808865 / 5.269862 (-2.460996) | 1.714713 / 4.565676 (-2.850963) | 0.111016 / 0.424275 (-0.313259) | 0.014688 / 0.007607 (0.007081) | 0.842542 / 0.226044 (0.616498) | 8.414336 / 2.268929 (6.145407) | 3.501021 / 55.444624 (-51.943604) | 2.665335 / 6.876477 (-4.211142) | 2.843706 / 2.142072 (0.701633) | 1.196398 / 4.805227 (-3.608829) | 0.245508 / 6.500664 (-6.255156) | 0.086970 / 0.075469 (0.011501) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.590244 / 1.841788 (-0.251544) | 18.694141 / 8.074308 (10.619833) | 21.752463 / 10.191392 (11.561071) | 0.264511 / 0.680424 (-0.415913) | 0.028713 / 0.534201 (-0.505488) | 0.531102 / 0.579283 (-0.048181) | 0.626302 / 0.434364 (0.191938) | 0.624541 / 0.540337 (0.084203) | 0.745745 / 1.386936 (-0.641191) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.010097 / 0.011353 (-0.001256) | 0.005558 / 0.011008 (-0.005451) | 0.111326 / 0.038508 (0.072818) | 0.036465 / 0.023109 (0.013356) | 0.472116 / 0.275898 (0.196218) | 0.524479 / 0.323480 (0.200999) | 0.007466 / 0.007986 (-0.000520) | 0.005440 / 0.004328 (0.001112) | 0.103482 / 0.004250 (0.099231) | 0.053217 / 0.037052 (0.016165) | 0.476685 / 0.258489 (0.218196) | 0.554011 / 0.293841 (0.260170) | 0.047157 / 0.128546 (-0.081390) | 0.015895 / 0.075646 (-0.059751) | 0.115997 / 0.419271 (-0.303274) | 0.062290 / 0.043533 (0.018758) | 0.474166 / 0.255139 (0.219027) | 0.498854 / 0.283200 (0.215655) | 0.121798 / 0.141683 (-0.019885) | 1.956583 / 1.452155 (0.504428) | 2.069620 / 1.492716 (0.576904) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.278637 / 0.018006 (0.260631) | 0.555295 / 0.000490 (0.554805) | 0.007401 / 0.000200 (0.007201) | 0.000121 / 0.000054 (0.000066) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.033576 / 0.037411 (-0.003835) | 0.136479 / 0.014526 (0.121954) | 0.153960 / 0.176557 (-0.022597) | 0.203422 / 0.737135 (-0.533713) | 0.154159 / 0.296338 (-0.142180) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.672561 / 0.215209 (0.457352) | 6.956675 / 2.077655 (4.879020) | 3.063636 / 1.504120 (1.559516) | 2.668256 / 1.541195 (1.127061) | 2.794793 / 1.468490 (1.326303) | 0.964242 / 4.584777 (-3.620535) | 5.785992 / 3.745712 (2.040279) | 2.850079 / 5.269862 (-2.419782) | 1.782491 / 4.565676 (-2.783186) | 0.114859 / 0.424275 (-0.309416) | 0.015229 / 0.007607 (0.007622) | 0.858406 / 0.226044 (0.632362) | 8.646296 / 2.268929 (6.377367) | 3.842133 / 55.444624 (-51.602492) | 3.180017 / 6.876477 (-3.696460) | 3.241315 / 2.142072 (1.099243) | 1.248988 / 4.805227 (-3.556239) | 0.235075 / 6.500664 (-6.265589) | 0.087192 / 0.075469 (0.011723) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.783877 / 1.841788 (-0.057910) | 19.477223 / 8.074308 (11.402914) | 22.926734 / 10.191392 (12.735342) | 0.246970 / 0.680424 (-0.433454) | 0.026386 / 0.534201 (-0.507815) | 0.517599 / 0.579283 (-0.061684) | 0.626504 / 0.434364 (0.192140) | 0.606943 / 0.540337 (0.066606) | 0.739115 / 1.386936 (-0.647821) |

</details>
</details>

![](https://cml.dev/watermark.png#e8f051a41454f8625091338e6b53119a5eb9b2a0 "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008085 / 0.011353 (-0.003268) | 0.005568 / 0.011008 (-0.005440) | 0.119674 / 0.038508 (0.081166) | 0.040452 / 0.023109 (0.017343) | 0.360288 / 0.275898 (0.084390) | 0.409448 / 0.323480 (0.085968) | 0.007281 / 0.007986 (-0.000705) | 0.004931 / 0.004328 (0.000602) | 0.089956 / 0.004250 (0.085706) | 0.056088 / 0.037052 (0.019036) | 0.384708 / 0.258489 (0.126219) | 0.423506 / 0.293841 (0.129665) | 0.033280 / 0.128546 (-0.095266) | 0.010696 / 0.075646 (-0.064951) | 0.394851 / 0.419271 (-0.024421) | 0.058412 / 0.043533 (0.014879) | 0.361514 / 0.255139 (0.106375) | 0.399121 / 0.283200 (0.115921) | 0.117927 / 0.141683 (-0.023756) | 1.791499 / 1.452155 (0.339344) | 1.889000 / 1.492716 (0.396284) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.253324 / 0.018006 (0.235318) | 0.536151 / 0.000490 (0.535661) | 0.010450 / 0.000200 (0.010250) | 0.000171 / 0.000054 (0.000117) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.034646 / 0.037411 (-0.002765) | 0.145999 / 0.014526 (0.131473) | 0.153793 / 0.176557 (-0.022763) | 0.232871 / 0.737135 (-0.504265) | 0.161151 / 0.296338 (-0.135188) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.471407 / 0.215209 (0.256197) | 4.715702 / 2.077655 (2.638047) | 2.228939 / 1.504120 (0.724819) | 2.008511 / 1.541195 (0.467317) | 2.135182 / 1.468490 (0.666692) | 0.620720 / 4.584777 (-3.964057) | 4.960731 / 3.745712 (1.215019) | 2.222469 / 5.269862 (-3.047393) | 1.284467 / 4.565676 (-3.281209) | 0.077931 / 0.424275 (-0.346344) | 0.013935 / 0.007607 (0.006328) | 0.593164 / 0.226044 (0.367120) | 5.940829 / 2.268929 (3.671900) | 2.664277 / 55.444624 (-52.780347) | 2.290655 / 6.876477 (-4.585822) | 2.496664 / 2.142072 (0.354592) | 0.759166 / 4.805227 (-4.046061) | 0.168011 / 6.500664 (-6.332653) | 0.077993 / 0.075469 (0.002524) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.440663 / 1.841788 (-0.401125) | 19.105377 / 8.074308 (11.031069) | 16.068118 / 10.191392 (5.876726) | 0.193024 / 0.680424 (-0.487400) | 0.022348 / 0.534201 (-0.511853) | 0.517454 / 0.579283 (-0.061829) | 0.528072 / 0.434364 (0.093708) | 0.565293 / 0.540337 (0.024955) | 0.676578 / 1.386936 (-0.710358) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.008089 / 0.011353 (-0.003264) | 0.005287 / 0.011008 (-0.005721) | 0.087964 / 0.038508 (0.049456) | 0.041548 / 0.023109 (0.018439) | 0.437733 / 0.275898 (0.161835) | 0.487878 / 0.323480 (0.164398) | 0.006898 / 0.007986 (-0.001087) | 0.004649 / 0.004328 (0.000320) | 0.086982 / 0.004250 (0.082732) | 0.056874 / 0.037052 (0.019822) | 0.437397 / 0.258489 (0.178908) | 0.490636 / 0.293841 (0.196795) | 0.033550 / 0.128546 (-0.094997) | 0.010430 / 0.075646 (-0.065216) | 0.096076 / 0.419271 (-0.323196) | 0.054028 / 0.043533 (0.010495) | 0.450262 / 0.255139 (0.195123) | 0.465566 / 0.283200 (0.182366) | 0.119987 / 0.141683 (-0.021696) | 1.764428 / 1.452155 (0.312273) | 1.841547 / 1.492716 (0.348831) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.271427 / 0.018006 (0.253420) | 0.506386 / 0.000490 (0.505896) | 0.001213 / 0.000200 (0.001013) | 0.000125 / 0.000054 (0.000070) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.036159 / 0.037411 (-0.001253) | 0.140578 / 0.014526 (0.126053) | 0.147517 / 0.176557 (-0.029040) | 0.206215 / 0.737135 (-0.530921) | 0.152560 / 0.296338 (-0.143779) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.522833 / 0.215209 (0.307624) | 5.215732 / 2.077655 (3.138077) | 2.553406 / 1.504120 (1.049286) | 2.344815 / 1.541195 (0.803620) | 2.422377 / 1.468490 (0.953886) | 0.631197 / 4.584777 (-3.953580) | 4.906216 / 3.745712 (1.160504) | 2.212923 / 5.269862 (-3.056938) | 1.352937 / 4.565676 (-3.212740) | 0.079141 / 0.424275 (-0.345135) | 0.013691 / 0.007607 (0.006084) | 0.634939 / 0.226044 (0.408895) | 6.578770 / 2.268929 (4.309842) | 3.080339 / 55.444624 (-52.364286) | 2.710243 / 6.876477 (-4.166234) | 2.740476 / 2.142072 (0.598404) | 0.783610 / 4.805227 (-4.021617) | 0.171589 / 6.500664 (-6.329075) | 0.077311 / 0.075469 (0.001842) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.584847 / 1.841788 (-0.256941) | 19.510132 / 8.074308 (11.435824) | 18.074572 / 10.191392 (7.883180) | 0.173494 / 0.680424 (-0.506930) | 0.021149 / 0.534201 (-0.513052) | 0.469026 / 0.579283 (-0.110258) | 0.518463 / 0.434364 (0.084099) | 0.550363 / 0.540337 (0.010026) | 0.667087 / 1.386936 (-0.719849) |

</details>
</details>

![](https://cml.dev/watermark.png#5dfcd876c25cc0ffbd6b5b518b017419390a8ada "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.007144 / 0.011353 (-0.004209) | 0.004783 / 0.011008 (-0.006225) | 0.103991 / 0.038508 (0.065483) | 0.039098 / 0.023109 (0.015989) | 0.319851 / 0.275898 (0.043952) | 0.356104 / 0.323480 (0.032625) | 0.007077 / 0.007986 (-0.000909) | 0.004188 / 0.004328 (-0.000141) | 0.078360 / 0.004250 (0.074109) | 0.050951 / 0.037052 (0.013899) | 0.321791 / 0.258489 (0.063302) | 0.356123 / 0.293841 (0.062283) | 0.028967 / 0.128546 (-0.099579) | 0.009091 / 0.075646 (-0.066555) | 0.355265 / 0.419271 (-0.064007) | 0.052521 / 0.043533 (0.008988) | 0.317333 / 0.255139 (0.062194) | 0.340747 / 0.283200 (0.057547) | 0.104354 / 0.141683 (-0.037329) | 1.522791 / 1.452155 (0.070636) | 1.579835 / 1.492716 (0.087118) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.260539 / 0.018006 (0.242532) | 0.454230 / 0.000490 (0.453740) | 0.036588 / 0.000200 (0.036388) | 0.000289 / 0.000054 (0.000235) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.028375 / 0.037411 (-0.009036) | 0.118939 / 0.014526 (0.104413) | 0.126553 / 0.176557 (-0.050004) | 0.184596 / 0.737135 (-0.552539) | 0.130583 / 0.296338 (-0.165755) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.417353 / 0.215209 (0.202144) | 4.171595 / 2.077655 (2.093940) | 1.855096 / 1.504120 (0.350976) | 1.673941 / 1.541195 (0.132747) | 1.761370 / 1.468490 (0.292880) | 0.544081 / 4.584777 (-4.040696) | 3.851877 / 3.745712 (0.106165) | 1.896661 / 5.269862 (-3.373200) | 1.093303 / 4.565676 (-3.472373) | 0.067967 / 0.424275 (-0.356308) | 0.012313 / 0.007607 (0.004706) | 0.532316 / 0.226044 (0.306272) | 5.336016 / 2.268929 (3.067087) | 2.344780 / 55.444624 (-53.099845) | 1.993909 / 6.876477 (-4.882568) | 2.167324 / 2.142072 (0.025251) | 0.670334 / 4.805227 (-4.134893) | 0.147705 / 6.500664 (-6.352959) | 0.067634 / 0.075469 (-0.007835) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.251005 / 1.841788 (-0.590783) | 15.405531 / 8.074308 (7.331223) | 14.197019 / 10.191392 (4.005627) | 0.144230 / 0.680424 (-0.536193) | 0.018352 / 0.534201 (-0.515849) | 0.427536 / 0.579283 (-0.151748) | 0.433135 / 0.434364 (-0.001229) | 0.502624 / 0.540337 (-0.037713) | 0.612312 / 1.386936 (-0.774624) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.007011 / 0.011353 (-0.004342) | 0.004857 / 0.011008 (-0.006151) | 0.077797 / 0.038508 (0.039289) | 0.035411 / 0.023109 (0.012302) | 0.368234 / 0.275898 (0.092336) | 0.408359 / 0.323480 (0.084879) | 0.005883 / 0.007986 (-0.002102) | 0.004311 / 0.004328 (-0.000017) | 0.077216 / 0.004250 (0.072966) | 0.052062 / 0.037052 (0.015010) | 0.368502 / 0.258489 (0.110013) | 0.428681 / 0.293841 (0.134840) | 0.028889 / 0.128546 (-0.099657) | 0.009146 / 0.075646 (-0.066501) | 0.085515 / 0.419271 (-0.333756) | 0.050216 / 0.043533 (0.006683) | 0.359562 / 0.255139 (0.104423) | 0.378335 / 0.283200 (0.095135) | 0.106351 / 0.141683 (-0.035332) | 1.538943 / 1.452155 (0.086788) | 1.663572 / 1.492716 (0.170855) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.216917 / 0.018006 (0.198911) | 0.444130 / 0.000490 (0.443641) | 0.002640 / 0.000200 (0.002440) | 0.000093 / 0.000054 (0.000038) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.032509 / 0.037411 (-0.004902) | 0.123955 / 0.014526 (0.109430) | 0.133236 / 0.176557 (-0.043321) | 0.187408 / 0.737135 (-0.549727) | 0.136696 / 0.296338 (-0.159643) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.443714 / 0.215209 (0.228505) | 4.416973 / 2.077655 (2.339318) | 2.145279 / 1.504120 (0.641159) | 1.946669 / 1.541195 (0.405474) | 2.044105 / 1.468490 (0.575614) | 0.534463 / 4.584777 (-4.050314) | 3.824926 / 3.745712 (0.079214) | 3.151796 / 5.269862 (-2.118066) | 1.497513 / 4.565676 (-3.068164) | 0.066799 / 0.424275 (-0.357476) | 0.012408 / 0.007607 (0.004801) | 0.544182 / 0.226044 (0.318138) | 5.419403 / 2.268929 (3.150474) | 2.605191 / 55.444624 (-52.839433) | 2.285354 / 6.876477 (-4.591123) | 2.359520 / 2.142072 (0.217448) | 0.655489 / 4.805227 (-4.149738) | 0.143496 / 6.500664 (-6.357168) | 0.066782 / 0.075469 (-0.008687) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.329370 / 1.841788 (-0.512418) | 16.058019 / 8.074308 (7.983711) | 15.119769 / 10.191392 (4.928377) | 0.147967 / 0.680424 (-0.532457) | 0.018360 / 0.534201 (-0.515841) | 0.436847 / 0.579283 (-0.142436) | 0.435136 / 0.434364 (0.000773) | 0.507176 / 0.540337 (-0.033161) | 0.610627 / 1.386936 (-0.776309) |

</details>
</details>

![](https://cml.dev/watermark.png#b4cc3ee6d8945052283076854eb77575d52b7432 "CML watermark")


<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.006425 / 0.011353 (-0.004927) | 0.003710 / 0.011008 (-0.007298) | 0.102072 / 0.038508 (0.063564) | 0.033974 / 0.023109 (0.010865) | 0.273146 / 0.275898 (-0.002752) | 0.313254 / 0.323480 (-0.010226) | 0.004889 / 0.007986 (-0.003096) | 0.004803 / 0.004328 (0.000475) | 0.067359 / 0.004250 (0.063109) | 0.040281 / 0.037052 (0.003228) | 0.302106 / 0.258489 (0.043617) | 0.318039 / 0.293841 (0.024198) | 0.028839 / 0.128546 (-0.099707) | 0.008726 / 0.075646 (-0.066921) | 0.322532 / 0.419271 (-0.096739) | 0.048845 / 0.043533 (0.005312) | 0.299836 / 0.255139 (0.044697) | 0.300983 / 0.283200 (0.017784) | 0.103384 / 0.141683 (-0.038299) | 1.417245 / 1.452155 (-0.034910) | 1.538819 / 1.492716 (0.046102) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.219798 / 0.018006 (0.201792) | 0.442297 / 0.000490 (0.441807) | 0.013792 / 0.000200 (0.013592) | 0.000101 / 0.000054 (0.000046) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.024996 / 0.037411 (-0.012416) | 0.098558 / 0.014526 (0.084032) | 0.116423 / 0.176557 (-0.060133) | 0.163481 / 0.737135 (-0.573654) | 0.115031 / 0.296338 (-0.181308) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.392411 / 0.215209 (0.177202) | 4.025992 / 2.077655 (1.948337) | 1.850809 / 1.504120 (0.346690) | 1.668330 / 1.541195 (0.127136) | 1.627041 / 1.468490 (0.158551) | 0.510721 / 4.584777 (-4.074055) | 3.841318 / 3.745712 (0.095606) | 3.416979 / 5.269862 (-1.852883) | 1.640796 / 4.565676 (-2.924880) | 0.061968 / 0.424275 (-0.362307) | 0.010281 / 0.007607 (0.002674) | 0.485592 / 0.226044 (0.259548) | 4.872205 / 2.268929 (2.603277) | 2.146753 / 55.444624 (-53.297871) | 1.832087 / 6.876477 (-5.044390) | 1.920928 / 2.142072 (-0.221144) | 0.606363 / 4.805227 (-4.198864) | 0.134351 / 6.500664 (-6.366313) | 0.057583 / 0.075469 (-0.017886) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.153048 / 1.841788 (-0.688739) | 14.165743 / 8.074308 (6.091435) | 12.237798 / 10.191392 (2.046406) | 0.159815 / 0.680424 (-0.520608) | 0.018226 / 0.534201 (-0.515975) | 0.372390 / 0.579283 (-0.206893) | 0.396552 / 0.434364 (-0.037811) | 0.439445 / 0.540337 (-0.100892) | 0.521924 / 1.386936 (-0.865012) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.006162 / 0.011353 (-0.005191) | 0.004006 / 0.011008 (-0.007002) | 0.067226 / 0.038508 (0.028718) | 0.030285 / 0.023109 (0.007176) | 0.361220 / 0.275898 (0.085322) | 0.386783 / 0.323480 (0.063303) | 0.005202 / 0.007986 (-0.002784) | 0.003453 / 0.004328 (-0.000876) | 0.068299 / 0.004250 (0.064048) | 0.041433 / 0.037052 (0.004381) | 0.360222 / 0.258489 (0.101733) | 0.399327 / 0.293841 (0.105486) | 0.026066 / 0.128546 (-0.102480) | 0.008025 / 0.075646 (-0.067621) | 0.079588 / 0.419271 (-0.339683) | 0.042616 / 0.043533 (-0.000917) | 0.347639 / 0.255139 (0.092500) | 0.386092 / 0.283200 (0.102893) | 0.100869 / 0.141683 (-0.040814) | 1.386901 / 1.452155 (-0.065254) | 1.471523 / 1.492716 (-0.021193) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.217020 / 0.018006 (0.199014) | 0.431033 / 0.000490 (0.430543) | 0.002902 / 0.000200 (0.002702) | 0.000092 / 0.000054 (0.000037) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.027396 / 0.037411 (-0.010015) | 0.114154 / 0.014526 (0.099629) | 0.117918 / 0.176557 (-0.058638) | 0.173342 / 0.737135 (-0.563794) | 0.125812 / 0.296338 (-0.170526) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.424843 / 0.215209 (0.209634) | 4.324828 / 2.077655 (2.247174) | 2.188263 / 1.504120 (0.684143) | 1.912288 / 1.541195 (0.371094) | 2.011621 / 1.468490 (0.543131) | 0.560944 / 4.584777 (-4.023833) | 3.975047 / 3.745712 (0.229335) | 3.130242 / 5.269862 (-2.139619) | 1.667902 / 4.565676 (-2.897775) | 0.062245 / 0.424275 (-0.362030) | 0.011300 / 0.007607 (0.003692) | 0.498571 / 0.226044 (0.272527) | 5.024887 / 2.268929 (2.755958) | 2.482967 / 55.444624 (-52.961657) | 2.216125 / 6.876477 (-4.660352) | 2.175856 / 2.142072 (0.033783) | 0.615207 / 4.805227 (-4.190021) | 0.133808 / 6.500664 (-6.366856) | 0.058681 / 0.075469 (-0.016788) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.370150 / 1.841788 (-0.471637) | 14.580907 / 8.074308 (6.506599) | 14.209955 / 10.191392 (4.018563) | 0.139738 / 0.680424 (-0.540686) | 0.018722 / 0.534201 (-0.515479) | 0.375755 / 0.579283 (-0.203528) | 0.428335 / 0.434364 (-0.006029) | 0.438957 / 0.540337 (-0.101380) | 0.541130 / 1.386936 (-0.845806) |

</details>
</details>

![](https://cml.dev/watermark.png#c14806a42a20f44a60f3663642bae1de199ab1ec "CML watermark")


@alvarobartt @lhoestq This should be ready for re-review. I've rebased it on the recent PR to allow `batch_size=None`, and it should also support unbatched loading now.

Having a variety of different methods like this is annoying, but once our minimum Python version is 3.8 I can go back and clear a lot of this out!

LGTM @Rocketknight1! I may run some tests during the weekend to compare performances with the current approach in case that's useful 😄 

@alvarobartt I'll probably merge now, just to avoid the major memory usage issues we currently have! Feel free to run the comparisons before/after the commit.

And yes, hopefully Py3.7 goes EOL and we make Py3.8 the minimum soon to resolve this.

> @alvarobartt I'll probably merge now, just to avoid the major memory usage issues we currently have! Feel free to run the comparisons before/after the commit.

I'll ping you back with the comparison this weekend! 🤗

<details>
<summary>Show benchmarks</summary>

PyArrow==8.0.0

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.007102 / 0.011353 (-0.004251) | 0.004713 / 0.011008 (-0.006295) | 0.102391 / 0.038508 (0.063883) | 0.038363 / 0.023109 (0.015253) | 0.330843 / 0.275898 (0.054945) | 0.365290 / 0.323480 (0.041810) | 0.006389 / 0.007986 (-0.001596) | 0.004287 / 0.004328 (-0.000041) | 0.078710 / 0.004250 (0.074460) | 0.051974 / 0.037052 (0.014922) | 0.333163 / 0.258489 (0.074674) | 0.371016 / 0.293841 (0.077176) | 0.028412 / 0.128546 (-0.100134) | 0.009350 / 0.075646 (-0.066296) | 0.351673 / 0.419271 (-0.067599) | 0.051879 / 0.043533 (0.008347) | 0.323769 / 0.255139 (0.068630) | 0.342994 / 0.283200 (0.059794) | 0.107347 / 0.141683 (-0.034336) | 1.585641 / 1.452155 (0.133487) | 1.679408 / 1.492716 (0.186691) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.251772 / 0.018006 (0.233766) | 0.580570 / 0.000490 (0.580081) | 0.008346 / 0.000200 (0.008147) | 0.000113 / 0.000054 (0.000059) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.028740 / 0.037411 (-0.008672) | 0.117707 / 0.014526 (0.103182) | 0.126397 / 0.176557 (-0.050160) | 0.183823 / 0.737135 (-0.553312) | 0.132272 / 0.296338 (-0.164066) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.428428 / 0.215209 (0.213219) | 4.263983 / 2.077655 (2.186329) | 2.012477 / 1.504120 (0.508357) | 1.812453 / 1.541195 (0.271259) | 1.889282 / 1.468490 (0.420792) | 0.534459 / 4.584777 (-4.050318) | 3.719460 / 3.745712 (-0.026252) | 1.958039 / 5.269862 (-3.311823) | 1.078166 / 4.565676 (-3.487510) | 0.067902 / 0.424275 (-0.356373) | 0.012479 / 0.007607 (0.004872) | 0.532071 / 0.226044 (0.306026) | 5.343323 / 2.268929 (3.074394) | 2.478577 / 55.444624 (-52.966047) | 2.146067 / 6.876477 (-4.730409) | 2.324783 / 2.142072 (0.182710) | 0.655925 / 4.805227 (-4.149302) | 0.145578 / 6.500664 (-6.355086) | 0.068044 / 0.075469 (-0.007425) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.254036 / 1.841788 (-0.587752) | 15.199639 / 8.074308 (7.125331) | 13.851406 / 10.191392 (3.660014) | 0.168760 / 0.680424 (-0.511664) | 0.017807 / 0.534201 (-0.516394) | 0.425857 / 0.579283 (-0.153426) | 0.413098 / 0.434364 (-0.021266) | 0.497433 / 0.540337 (-0.042905) | 0.599273 / 1.386936 (-0.787663) |

</details>
PyArrow==latest

<details>
<summary>Show updated benchmarks!</summary>

### Benchmark: benchmark_array_xd.json

| metric | read_batch_formatted_as_numpy after write_array2d | read_batch_formatted_as_numpy after write_flattened_sequence | read_batch_formatted_as_numpy after write_nested_sequence | read_batch_unformated after write_array2d | read_batch_unformated after write_flattened_sequence | read_batch_unformated after write_nested_sequence | read_col_formatted_as_numpy after write_array2d | read_col_formatted_as_numpy after write_flattened_sequence | read_col_formatted_as_numpy after write_nested_sequence | read_col_unformated after write_array2d | read_col_unformated after write_flattened_sequence | read_col_unformated after write_nested_sequence | read_formatted_as_numpy after write_array2d | read_formatted_as_numpy after write_flattened_sequence | read_formatted_as_numpy after write_nested_sequence | read_unformated after write_array2d | read_unformated after write_flattened_sequence | read_unformated after write_nested_sequence | write_array2d | write_flattened_sequence | write_nested_sequence |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.007044 / 0.011353 (-0.004309) | 0.005036 / 0.011008 (-0.005972) | 0.080307 / 0.038508 (0.041798) | 0.035926 / 0.023109 (0.012817) | 0.402026 / 0.275898 (0.126128) | 0.444185 / 0.323480 (0.120705) | 0.006228 / 0.007986 (-0.001758) | 0.004481 / 0.004328 (0.000153) | 0.080223 / 0.004250 (0.075972) | 0.055385 / 0.037052 (0.018333) | 0.405674 / 0.258489 (0.147184) | 0.461574 / 0.293841 (0.167733) | 0.029237 / 0.128546 (-0.099309) | 0.009249 / 0.075646 (-0.066398) | 0.086215 / 0.419271 (-0.333056) | 0.048512 / 0.043533 (0.004979) | 0.401374 / 0.255139 (0.146235) | 0.418274 / 0.283200 (0.135074) | 0.107994 / 0.141683 (-0.033689) | 1.560504 / 1.452155 (0.108350) | 1.669651 / 1.492716 (0.176935) |

### Benchmark: benchmark_getitem\_100B.json

| metric | get_batch_of\_1024\_random_rows | get_batch_of\_1024\_rows | get_first_row | get_last_row |
|--------|---|---|---|---|
| new / old (diff) | 0.275393 / 0.018006 (0.257387) | 0.573688 / 0.000490 (0.573199) | 0.007236 / 0.000200 (0.007036) | 0.000153 / 0.000054 (0.000099) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.033387 / 0.037411 (-0.004024) | 0.125027 / 0.014526 (0.110501) | 0.138601 / 0.176557 (-0.037956) | 0.191820 / 0.737135 (-0.545315) | 0.141022 / 0.296338 (-0.155317) |

### Benchmark: benchmark_iterating.json

| metric | read 5000 | read 50000 | read_batch 50000 10 | read_batch 50000 100 | read_batch 50000 1000 | read_formatted numpy 5000 | read_formatted pandas 5000 | read_formatted tensorflow 5000 | read_formatted torch 5000 | read_formatted_batch numpy 5000 10 | read_formatted_batch numpy 5000 1000 | shuffled read 5000 | shuffled read 50000 | shuffled read_batch 50000 10 | shuffled read_batch 50000 100 | shuffled read_batch 50000 1000 | shuffled read_formatted numpy 5000 | shuffled read_formatted_batch numpy 5000 10 | shuffled read_formatted_batch numpy 5000 1000 |
|--------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 0.456382 / 0.215209 (0.241173) | 4.559197 / 2.077655 (2.481542) | 2.263333 / 1.504120 (0.759213) | 2.073151 / 1.541195 (0.531956) | 2.185314 / 1.468490 (0.716824) | 0.540230 / 4.584777 (-4.044547) | 3.934984 / 3.745712 (0.189272) | 1.980895 / 5.269862 (-3.288966) | 1.101440 / 4.565676 (-3.464237) | 0.068255 / 0.424275 (-0.356020) | 0.012605 / 0.007607 (0.004997) | 0.560695 / 0.226044 (0.334650) | 5.588877 / 2.268929 (3.319948) | 2.756690 / 55.444624 (-52.687935) | 2.427774 / 6.876477 (-4.448702) | 2.548903 / 2.142072 (0.406831) | 0.657177 / 4.805227 (-4.148050) | 0.147645 / 6.500664 (-6.353019) | 0.069216 / 0.075469 (-0.006253) |

### Benchmark: benchmark_map_filter.json

| metric | filter | map fast-tokenizer batched | map identity | map identity batched | map no-op batched | map no-op batched numpy | map no-op batched pandas | map no-op batched pytorch | map no-op batched tensorflow |
|--------|---|---|---|---|---|---|---|---|---|
| new / old (diff) | 1.319813 / 1.841788 (-0.521975) | 15.882227 / 8.074308 (7.807919) | 15.324481 / 10.191392 (5.133089) | 0.193708 / 0.680424 (-0.486716) | 0.018264 / 0.534201 (-0.515937) | 0.432594 / 0.579283 (-0.146689) | 0.437063 / 0.434364 (0.002699) | 0.512297 / 0.540337 (-0.028040) | 0.617469 / 1.386936 (-0.769467) |

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