Document that removing all the columns returns an empty document and the num_row is lost


Comments:
_The documentation is not available anymore as the PR was closed or merged._

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

PyArrow==6.0.0

<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) | 0.011812 / 0.011353 (0.000459) | 0.006878 / 0.011008 (-0.004130) | 0.128720 / 0.038508 (0.090212) | 0.038506 / 0.023109 (0.015397) | 0.359670 / 0.275898 (0.083772) | 0.422908 / 0.323480 (0.099428) | 0.010115 / 0.007986 (0.002129) | 0.004332 / 0.004328 (0.000004) | 0.096281 / 0.004250 (0.092031) | 0.048850 / 0.037052 (0.011798) | 0.373795 / 0.258489 (0.115306) | 0.414643 / 0.293841 (0.120802) | 0.057568 / 0.128546 (-0.070978) | 0.024135 / 0.075646 (-0.051512) | 0.411764 / 0.419271 (-0.007507) | 0.060167 / 0.043533 (0.016634) | 0.367119 / 0.255139 (0.111980) | 0.391813 / 0.283200 (0.108613) | 0.112125 / 0.141683 (-0.029558) | 1.869560 / 1.452155 (0.417406) | 1.845649 / 1.492716 (0.352932) |

### 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) | 0.211449 / 0.018006 (0.193443) | 0.522453 / 0.000490 (0.521963) | 0.003984 / 0.000200 (0.003784) | 0.000096 / 0.000054 (0.000042) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.026015 / 0.037411 (-0.011397) | 0.117747 / 0.014526 (0.103221) | 0.125037 / 0.176557 (-0.051520) | 0.168351 / 0.737135 (-0.568785) | 0.132390 / 0.296338 (-0.163949) |

### 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) | 0.605653 / 0.215209 (0.390444) | 5.883452 / 2.077655 (3.805798) | 2.367052 / 1.504120 (0.862932) | 2.137671 / 1.541195 (0.596476) | 2.042370 / 1.468490 (0.573880) | 1.168442 / 4.584777 (-3.416335) | 5.205236 / 3.745712 (1.459524) | 2.992514 / 5.269862 (-2.277348) | 2.191829 / 4.565676 (-2.373847) | 0.137702 / 0.424275 (-0.286574) | 0.015898 / 0.007607 (0.008291) | 0.783987 / 0.226044 (0.557942) | 7.768965 / 2.268929 (5.500036) | 3.249149 / 55.444624 (-52.195476) | 2.530687 / 6.876477 (-4.345790) | 2.675212 / 2.142072 (0.533140) | 1.482804 / 4.805227 (-3.322423) | 0.276845 / 6.500664 (-6.223819) | 0.080597 / 0.075469 (0.005128) |

### 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) | 1.519086 / 1.841788 (-0.322701) | 17.394093 / 8.074308 (9.319785) | 19.613554 / 10.191392 (9.422162) | 0.253291 / 0.680424 (-0.427133) | 0.047746 / 0.534201 (-0.486455) | 0.547114 / 0.579283 (-0.032170) | 0.623873 / 0.434364 (0.189509) | 0.631924 / 0.540337 (0.091586) | 0.744390 / 1.386936 (-0.642546) |

</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) | 0.009229 / 0.011353 (-0.002124) | 0.006206 / 0.011008 (-0.004802) | 0.121866 / 0.038508 (0.083357) | 0.033629 / 0.023109 (0.010519) | 0.435172 / 0.275898 (0.159274) | 0.472093 / 0.323480 (0.148613) | 0.006946 / 0.007986 (-0.001039) | 0.004848 / 0.004328 (0.000519) | 0.097289 / 0.004250 (0.093038) | 0.046982 / 0.037052 (0.009930) | 0.447365 / 0.258489 (0.188876) | 0.491213 / 0.293841 (0.197372) | 0.055486 / 0.128546 (-0.073060) | 0.019788 / 0.075646 (-0.055858) | 0.399830 / 0.419271 (-0.019441) | 0.058943 / 0.043533 (0.015411) | 0.447658 / 0.255139 (0.192519) | 0.465752 / 0.283200 (0.182552) | 0.110441 / 0.141683 (-0.031242) | 1.773155 / 1.452155 (0.321001) | 1.899370 / 1.492716 (0.406653) |

### 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) | 0.191188 / 0.018006 (0.173181) | 0.523721 / 0.000490 (0.523232) | 0.004008 / 0.000200 (0.003808) | 0.000126 / 0.000054 (0.000072) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.032579 / 0.037411 (-0.004833) | 0.120870 / 0.014526 (0.106344) | 0.154991 / 0.176557 (-0.021565) | 0.175450 / 0.737135 (-0.561685) | 0.136526 / 0.296338 (-0.159813) |

### 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) | 0.627262 / 0.215209 (0.412052) | 6.457989 / 2.077655 (4.380334) | 2.935188 / 1.504120 (1.431068) | 2.558705 / 1.541195 (1.017510) | 2.669455 / 1.468490 (1.200965) | 1.228791 / 4.584777 (-3.355985) | 5.621262 / 3.745712 (1.875549) | 3.181775 / 5.269862 (-2.088086) | 2.115116 / 4.565676 (-2.450560) | 0.159348 / 0.424275 (-0.264927) | 0.013598 / 0.007607 (0.005991) | 0.834732 / 0.226044 (0.608687) | 8.051097 / 2.268929 (5.782168) | 3.761681 / 55.444624 (-51.682943) | 2.898158 / 6.876477 (-3.978319) | 2.936289 / 2.142072 (0.794217) | 1.476307 / 4.805227 (-3.328920) | 0.269845 / 6.500664 (-6.230819) | 0.087225 / 0.075469 (0.011756) |

### 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) | 1.632522 / 1.841788 (-0.209266) | 17.615297 / 8.074308 (9.540989) | 20.501172 / 10.191392 (10.309780) | 0.248845 / 0.680424 (-0.431579) | 0.024852 / 0.534201 (-0.509349) | 0.498957 / 0.579283 (-0.080326) | 0.588566 / 0.434364 (0.154202) | 0.611051 / 0.540337 (0.070714) | 0.726321 / 1.386936 (-0.660615) |

</details>
</details>

![](https://cml.dev/watermark.png#adaaf0b5ad596538c744d41bb56ce472834b6573 "CML watermark")


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

PyArrow==6.0.0

<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) | 0.008920 / 0.011353 (-0.002433) | 0.004666 / 0.011008 (-0.006342) | 0.098584 / 0.038508 (0.060076) | 0.030213 / 0.023109 (0.007103) | 0.298180 / 0.275898 (0.022282) | 0.358932 / 0.323480 (0.035452) | 0.007182 / 0.007986 (-0.000804) | 0.005430 / 0.004328 (0.001102) | 0.077962 / 0.004250 (0.073712) | 0.038516 / 0.037052 (0.001463) | 0.308840 / 0.258489 (0.050351) | 0.343678 / 0.293841 (0.049837) | 0.033701 / 0.128546 (-0.094845) | 0.011460 / 0.075646 (-0.064186) | 0.319809 / 0.419271 (-0.099462) | 0.040731 / 0.043533 (-0.002802) | 0.299772 / 0.255139 (0.044633) | 0.324292 / 0.283200 (0.041092) | 0.087755 / 0.141683 (-0.053928) | 1.493077 / 1.452155 (0.040922) | 1.527462 / 1.492716 (0.034746) |

### 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) | 0.187927 / 0.018006 (0.169921) | 0.412785 / 0.000490 (0.412296) | 0.003235 / 0.000200 (0.003035) | 0.000080 / 0.000054 (0.000026) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.023313 / 0.037411 (-0.014098) | 0.095663 / 0.014526 (0.081137) | 0.105094 / 0.176557 (-0.071463) | 0.140389 / 0.737135 (-0.596746) | 0.108477 / 0.296338 (-0.187861) |

### 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) | 0.410680 / 0.215209 (0.195471) | 4.109287 / 2.077655 (2.031632) | 1.833214 / 1.504120 (0.329094) | 1.622837 / 1.541195 (0.081642) | 1.679899 / 1.468490 (0.211409) | 0.686920 / 4.584777 (-3.897857) | 3.463267 / 3.745712 (-0.282445) | 1.867035 / 5.269862 (-3.402826) | 1.150631 / 4.565676 (-3.415046) | 0.081209 / 0.424275 (-0.343066) | 0.012384 / 0.007607 (0.004777) | 0.521070 / 0.226044 (0.295026) | 5.208829 / 2.268929 (2.939900) | 2.289032 / 55.444624 (-53.155592) | 1.942976 / 6.876477 (-4.933501) | 1.990660 / 2.142072 (-0.151413) | 0.802976 / 4.805227 (-4.002252) | 0.148199 / 6.500664 (-6.352465) | 0.064644 / 0.075469 (-0.010825) |

### 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) | 1.277029 / 1.841788 (-0.564759) | 13.915489 / 8.074308 (5.841181) | 14.035486 / 10.191392 (3.844094) | 0.138205 / 0.680424 (-0.542219) | 0.028968 / 0.534201 (-0.505232) | 0.394275 / 0.579283 (-0.185008) | 0.399967 / 0.434364 (-0.034397) | 0.460595 / 0.540337 (-0.079742) | 0.537625 / 1.386936 (-0.849311) |

</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) | 0.006485 / 0.011353 (-0.004868) | 0.004534 / 0.011008 (-0.006474) | 0.097742 / 0.038508 (0.059234) | 0.027231 / 0.023109 (0.004122) | 0.431321 / 0.275898 (0.155423) | 0.469212 / 0.323480 (0.145732) | 0.004894 / 0.007986 (-0.003092) | 0.004147 / 0.004328 (-0.000181) | 0.073650 / 0.004250 (0.069400) | 0.037052 / 0.037052 (-0.000000) | 0.434196 / 0.258489 (0.175707) | 0.480539 / 0.293841 (0.186698) | 0.031923 / 0.128546 (-0.096623) | 0.011522 / 0.075646 (-0.064124) | 0.317062 / 0.419271 (-0.102209) | 0.041124 / 0.043533 (-0.002409) | 0.432013 / 0.255139 (0.176874) | 0.456760 / 0.283200 (0.173560) | 0.089757 / 0.141683 (-0.051925) | 1.497752 / 1.452155 (0.045597) | 1.585342 / 1.492716 (0.092626) |

### 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) | 0.227784 / 0.018006 (0.209778) | 0.404570 / 0.000490 (0.404080) | 0.000556 / 0.000200 (0.000356) | 0.000065 / 0.000054 (0.000011) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.025201 / 0.037411 (-0.012210) | 0.099348 / 0.014526 (0.084822) | 0.114984 / 0.176557 (-0.061573) | 0.147039 / 0.737135 (-0.590097) | 0.109727 / 0.296338 (-0.186611) |

### 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) | 0.468415 / 0.215209 (0.253206) | 4.692228 / 2.077655 (2.614573) | 2.403382 / 1.504120 (0.899262) | 2.196026 / 1.541195 (0.654832) | 2.234736 / 1.468490 (0.766246) | 0.703011 / 4.584777 (-3.881766) | 3.451513 / 3.745712 (-0.294199) | 2.596811 / 5.269862 (-2.673051) | 1.544079 / 4.565676 (-3.021598) | 0.083153 / 0.424275 (-0.341123) | 0.012605 / 0.007607 (0.004998) | 0.570265 / 0.226044 (0.344220) | 5.735996 / 2.268929 (3.467067) | 2.865336 / 55.444624 (-52.579288) | 2.508340 / 6.876477 (-4.368137) | 2.547144 / 2.142072 (0.405072) | 0.813018 / 4.805227 (-3.992210) | 0.150327 / 6.500664 (-6.350337) | 0.065837 / 0.075469 (-0.009632) |

### 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) | 1.268941 / 1.841788 (-0.572847) | 13.835698 / 8.074308 (5.761390) | 13.992726 / 10.191392 (3.801334) | 0.127751 / 0.680424 (-0.552673) | 0.016673 / 0.534201 (-0.517528) | 0.381921 / 0.579283 (-0.197362) | 0.390688 / 0.434364 (-0.043676) | 0.446234 / 0.540337 (-0.094103) | 0.532631 / 1.386936 (-0.854305) |

</details>
</details>

![](https://cml.dev/watermark.png#1492df3311bfeac55aaedf34c93c014630c4403e "CML watermark")


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

PyArrow==6.0.0

<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) | 0.008486 / 0.011353 (-0.002867) | 0.004573 / 0.011008 (-0.006435) | 0.100096 / 0.038508 (0.061588) | 0.029449 / 0.023109 (0.006340) | 0.298384 / 0.275898 (0.022486) | 0.361886 / 0.323480 (0.038406) | 0.006813 / 0.007986 (-0.001173) | 0.003394 / 0.004328 (-0.000935) | 0.077563 / 0.004250 (0.073312) | 0.035605 / 0.037052 (-0.001447) | 0.306864 / 0.258489 (0.048375) | 0.346438 / 0.293841 (0.052597) | 0.033156 / 0.128546 (-0.095390) | 0.011567 / 0.075646 (-0.064079) | 0.322189 / 0.419271 (-0.097083) | 0.040161 / 0.043533 (-0.003372) | 0.299329 / 0.255139 (0.044190) | 0.326375 / 0.283200 (0.043175) | 0.086572 / 0.141683 (-0.055111) | 1.502473 / 1.452155 (0.050319) | 1.528539 / 1.492716 (0.035823) |

### 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) | 0.008502 / 0.018006 (-0.009505) | 0.411045 / 0.000490 (0.410555) | 0.003179 / 0.000200 (0.002980) | 0.000073 / 0.000054 (0.000018) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.023177 / 0.037411 (-0.014234) | 0.096948 / 0.014526 (0.082422) | 0.104068 / 0.176557 (-0.072489) | 0.138739 / 0.737135 (-0.598396) | 0.108241 / 0.296338 (-0.188097) |

### 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) | 0.411156 / 0.215209 (0.195947) | 4.092992 / 2.077655 (2.015337) | 1.841903 / 1.504120 (0.337783) | 1.637449 / 1.541195 (0.096254) | 1.670968 / 1.468490 (0.202478) | 0.697301 / 4.584777 (-3.887476) | 3.354717 / 3.745712 (-0.390995) | 1.851518 / 5.269862 (-3.418344) | 1.160367 / 4.565676 (-3.405309) | 0.082613 / 0.424275 (-0.341662) | 0.012477 / 0.007607 (0.004870) | 0.524839 / 0.226044 (0.298795) | 5.264173 / 2.268929 (2.995245) | 2.294530 / 55.444624 (-53.150094) | 1.933233 / 6.876477 (-4.943244) | 1.968959 / 2.142072 (-0.173113) | 0.817104 / 4.805227 (-3.988123) | 0.149072 / 6.500664 (-6.351592) | 0.064911 / 0.075469 (-0.010558) |

### 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) | 1.222215 / 1.841788 (-0.619573) | 13.607545 / 8.074308 (5.533237) | 13.990230 / 10.191392 (3.798838) | 0.150855 / 0.680424 (-0.529568) | 0.028844 / 0.534201 (-0.505357) | 0.396169 / 0.579283 (-0.183114) | 0.406957 / 0.434364 (-0.027407) | 0.464069 / 0.540337 (-0.076268) | 0.554027 / 1.386936 (-0.832909) |

</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) | 0.006296 / 0.011353 (-0.005057) | 0.004563 / 0.011008 (-0.006445) | 0.097719 / 0.038508 (0.059211) | 0.027106 / 0.023109 (0.003996) | 0.409333 / 0.275898 (0.133435) | 0.445397 / 0.323480 (0.121917) | 0.004906 / 0.007986 (-0.003080) | 0.003316 / 0.004328 (-0.001012) | 0.075363 / 0.004250 (0.071112) | 0.039366 / 0.037052 (0.002314) | 0.412710 / 0.258489 (0.154221) | 0.451789 / 0.293841 (0.157948) | 0.031810 / 0.128546 (-0.096736) | 0.011681 / 0.075646 (-0.063965) | 0.318484 / 0.419271 (-0.100788) | 0.046741 / 0.043533 (0.003208) | 0.411631 / 0.255139 (0.156492) | 0.435274 / 0.283200 (0.152074) | 0.092366 / 0.141683 (-0.049317) | 1.492243 / 1.452155 (0.040089) | 1.617603 / 1.492716 (0.124887) |

### 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) | 0.217376 / 0.018006 (0.199369) | 0.400940 / 0.000490 (0.400450) | 0.003700 / 0.000200 (0.003500) | 0.000075 / 0.000054 (0.000021) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.023733 / 0.037411 (-0.013678) | 0.098553 / 0.014526 (0.084027) | 0.105790 / 0.176557 (-0.070767) | 0.139537 / 0.737135 (-0.597598) | 0.109862 / 0.296338 (-0.186477) |

### 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) | 0.476562 / 0.215209 (0.261353) | 4.773469 / 2.077655 (2.695814) | 2.447302 / 1.504120 (0.943182) | 2.240596 / 1.541195 (0.699401) | 2.271370 / 1.468490 (0.802880) | 0.698913 / 4.584777 (-3.885864) | 3.345648 / 3.745712 (-0.400064) | 1.845008 / 5.269862 (-3.424854) | 1.163213 / 4.565676 (-3.402464) | 0.082456 / 0.424275 (-0.341819) | 0.012315 / 0.007607 (0.004708) | 0.575881 / 0.226044 (0.349836) | 5.769575 / 2.268929 (3.500647) | 2.909759 / 55.444624 (-52.534865) | 2.580259 / 6.876477 (-4.296218) | 2.590473 / 2.142072 (0.448401) | 0.802765 / 4.805227 (-4.002462) | 0.151514 / 6.500664 (-6.349150) | 0.067718 / 0.075469 (-0.007751) |

### 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) | 1.293014 / 1.841788 (-0.548773) | 13.934072 / 8.074308 (5.859763) | 13.538760 / 10.191392 (3.347368) | 0.126490 / 0.680424 (-0.553934) | 0.016653 / 0.534201 (-0.517548) | 0.381220 / 0.579283 (-0.198064) | 0.387571 / 0.434364 (-0.046793) | 0.444674 / 0.540337 (-0.095663) | 0.550802 / 1.386936 (-0.836134) |

</details>
</details>

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