Title: Use schema metadata only if it matches features
Author: lhoestq (MEMBER)
State: closed
Created: 2024-01-25T11:01:14Z

e.g. if we use `map` in arrow format and transform the table, the returned table might have new columns but the metadata might be wrong

Comments:
The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/datasets/pr_6616). All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

<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) | 0.005382 / 0.011353 (-0.005970) | 0.003853 / 0.011008 (-0.007155) | 0.062629 / 0.038508 (0.024121) | 0.030344 / 0.023109 (0.007234) | 0.245394 / 0.275898 (-0.030505) | 0.266004 / 0.323480 (-0.057476) | 0.003183 / 0.007986 (-0.004802) | 0.002795 / 0.004328 (-0.001533) | 0.048357 / 0.004250 (0.044107) | 0.043834 / 0.037052 (0.006782) | 0.255979 / 0.258489 (-0.002510) | 0.280803 / 0.293841 (-0.013038) | 0.028200 / 0.128546 (-0.100347) | 0.010856 / 0.075646 (-0.064791) | 0.207076 / 0.419271 (-0.212195) | 0.036286 / 0.043533 (-0.007247) | 0.246492 / 0.255139 (-0.008647) | 0.265861 / 0.283200 (-0.017338) | 0.018309 / 0.141683 (-0.123374) | 1.155136 / 1.452155 (-0.297018) | 1.214342 / 1.492716 (-0.278375) |

### 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) | 0.092530 / 0.018006 (0.074524) | 0.344951 / 0.000490 (0.344461) | 0.000207 / 0.000200 (0.000007) | 0.000043 / 0.000054 (-0.000011) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.018324 / 0.037411 (-0.019087) | 0.063137 / 0.014526 (0.048611) | 0.074683 / 0.176557 (-0.101874) | 0.120224 / 0.737135 (-0.616912) | 0.083107 / 0.296338 (-0.213232) |

### 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) | 0.288631 / 0.215209 (0.073422) | 2.817992 / 2.077655 (0.740337) | 1.473609 / 1.504120 (-0.030511) | 1.336610 / 1.541195 (-0.204585) | 1.354807 / 1.468490 (-0.113683) | 0.568776 / 4.584777 (-4.016001) | 2.412607 / 3.745712 (-1.333105) | 2.832816 / 5.269862 (-2.437045) | 1.789899 / 4.565676 (-2.775778) | 0.063602 / 0.424275 (-0.360673) | 0.004993 / 0.007607 (-0.002615) | 0.338830 / 0.226044 (0.112786) | 3.302550 / 2.268929 (1.033621) | 1.827907 / 55.444624 (-53.616717) | 1.589857 / 6.876477 (-5.286620) | 1.647746 / 2.142072 (-0.494326) | 0.658461 / 4.805227 (-4.146766) | 0.120360 / 6.500664 (-6.380304) | 0.042989 / 0.075469 (-0.032480) |

### 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) | 0.945487 / 1.841788 (-0.896301) | 11.846335 / 8.074308 (3.772027) | 10.483199 / 10.191392 (0.291807) | 0.131853 / 0.680424 (-0.548570) | 0.014230 / 0.534201 (-0.519971) | 0.288700 / 0.579283 (-0.290584) | 0.276086 / 0.434364 (-0.158278) | 0.326225 / 0.540337 (-0.214112) | 0.422874 / 1.386936 (-0.964062) |

</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) | 0.006234 / 0.011353 (-0.005118) | 0.004104 / 0.011008 (-0.006904) | 0.049967 / 0.038508 (0.011459) | 0.037157 / 0.023109 (0.014048) | 0.261892 / 0.275898 (-0.014006) | 0.284304 / 0.323480 (-0.039176) | 0.004482 / 0.007986 (-0.003504) | 0.002920 / 0.004328 (-0.001409) | 0.048827 / 0.004250 (0.044577) | 0.052258 / 0.037052 (0.015206) | 0.277121 / 0.258489 (0.018632) | 0.304177 / 0.293841 (0.010336) | 0.053537 / 0.128546 (-0.075009) | 0.011137 / 0.075646 (-0.064509) | 0.058188 / 0.419271 (-0.361083) | 0.034283 / 0.043533 (-0.009250) | 0.261912 / 0.255139 (0.006773) | 0.273851 / 0.283200 (-0.009348) | 0.017824 / 0.141683 (-0.123859) | 1.130454 / 1.452155 (-0.321701) | 1.176834 / 1.492716 (-0.315882) |

### 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) | 0.102104 / 0.018006 (0.084098) | 0.302873 / 0.000490 (0.302383) | 0.000208 / 0.000200 (0.000008) | 0.000052 / 0.000054 (-0.000003) |

### Benchmark: benchmark_indices_mapping.json

| metric | select | shard | shuffle | sort | train_test_split |
|--------|---|---|---|---|---|
| new / old (diff) | 0.022470 / 0.037411 (-0.014941) | 0.076776 / 0.014526 (0.062250) | 0.088220 / 0.176557 (-0.088337) | 0.130030 / 0.737135 (-0.607105) | 0.089955 / 0.296338 (-0.206383) |

### 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) | 0.284070 / 0.215209 (0.068861) | 2.769130 / 2.077655 (0.691475) | 1.546379 / 1.504120 (0.042259) | 1.435849 / 1.541195 (-0.105346) | 1.478616 / 1.468490 (0.010126) | 0.569185 / 4.584777 (-4.015592) | 2.504721 / 3.745712 (-1.240992) | 2.778267 / 5.269862 (-2.491595) | 1.860360 / 4.565676 (-2.705316) | 0.073465 / 0.424275 (-0.350810) | 0.005108 / 0.007607 (-0.002499) | 0.335185 / 0.226044 (0.109140) | 3.314799 / 2.268929 (1.045870) | 1.934824 / 55.444624 (-53.509801) | 1.656247 / 6.876477 (-5.220229) | 1.785422 / 2.142072 (-0.356650) | 0.673677 / 4.805227 (-4.131551) | 0.117692 / 6.500664 (-6.382972) | 0.041648 / 0.075469 (-0.033821) |

### 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) | 0.972143 / 1.841788 (-0.869645) | 12.980353 / 8.074308 (4.906045) | 11.056189 / 10.191392 (0.864797) | 0.134592 / 0.680424 (-0.545832) | 0.015972 / 0.534201 (-0.518229) | 0.301691 / 0.579283 (-0.277593) | 0.286332 / 0.434364 (-0.148032) | 0.329025 / 0.540337 (-0.211312) | 0.422585 / 1.386936 (-0.964351) |

</details>
</details>

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