No sampling over 281TB #19978
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No sampling over 281TB #19978
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Mytherin
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Nov 29, 2025
| auto rows = sample_value.GetValue<int64_t>(); | ||
| if (rows < 0) { | ||
| throw ParserException("Sample rows %lld out of range, must be bigger than or equal to 0", rows); | ||
| if (rows < 0 || sample_value.GetValue<uint64_t>() >= Allocator::MAXIMUM_ALLOC_SIZE) { |
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The sample size is in rows but the allocator max size is in bytes - I suspect that sampling for 281474976710656-1 rows will still throw the allocation error. Should we reduce the limit further / add a test for this?
Alternatively, we might want to not allocate all the space for the sample up-front if the sample size is very large - but that's obviously a larger change.
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Have updated it so that no more than 1 billion rows can be requested. No to get an internal error every row sampled would need 281kb of data for the allocation limit to be reached. I can reduce the max row limit if desired |
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No sampling over 281TB (duckdb/duckdb#19978)
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No sampling over 281TB (duckdb/duckdb#19978) Co-authored-by: krlmlr <krlmlr@users.noreply.github.com>
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Disable sampling over the Allocator::MAXIMUM_ALLOC_SIZE.
Error is thrown in the same place as what might happen if someone samples -1 rows.
Fixes #17780
Fixes https://github.com/duckdblabs/duckdb-internal/issues/5065