Reshard parquet per row group (1 shard == 1 row group == 1 episode) and feed the
episode-pool shuffle with max_buffer_input_shards so the pool is a uniform random
sample of the corpus, independent of episodes-per-file. Add validate_row_groups
guardrails (collapsed-row-group + distributed divisibility), require datasets>=5.0.0,
make the test fixture write one row group per episode, and plumb max_buffer_input_shards
through the dataloading benchmark.
Co-authored-by: Cursor <cursoragent@cursor.com>
Single-file SLURM-oriented benchmark comparing the map-style and native
streaming loaders on single-image samples: a self-submitting serial chain
that measures peak RSS, samples/s (and decoded frames/s), fetch-vs-decode
split, shuffle randomness, and p50/p95/p99 sample latency over a fixed
wall-clock window, including a 2-node split_dataset_by_node leg.
Co-authored-by: Cursor <cursoragent@cursor.com>
pepijn