Add unsorted decompressed chunk path even if we have sorted ones #6879
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The unsorted paths are better for hash aggregation, but currently in this case we are only going to add sorted paths.
Add ANALYZE. To keep the desired MergeAppend plans, we also have to add a LIMIT everywhere so that the MergeAppend is chosen based on its lower startup cost. Otherwise the plain Sort over Append will be chosen because for small tables its cost is less.
Add ANALYZE after compression. The plan changes are expected, SeqScans are preferred over IndexScans and Sort over MergeAppend for small tables.
We would add extra Sort nodes when adjusting the children of space partitioning MergeAppend under ChunkAppend. This is not needed because MergeAppend plans add the required Sort themselves, and in general no adjustment seems to be required for the MergeAppend children specifically there.
…append_partially_compressed-*
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@fabriziomello, @erimatnor: please review this pull request.
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…ppend_partially_compressed-* ordered_append-*
…y_compressed-* ordered_append-*
…append_partially_compressed-* ordered_append-*
svenklemm
reviewed
Dec 17, 2024
src/planner/planner.h
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| #define IS_UPDL_CMD(parse) \ | ||
| ((parse)->commandType == CMD_UPDATE || (parse)->commandType == CMD_DELETE) | ||
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can we just drop this macro, i dont think it adds much clarity
This reverts commit e94bd26.
akuzm
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Dec 19, 2024
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| Group Key: _hyper_31_114_chunk.device_id | ||
| -> Sort | ||
| Sort Key: _hyper_31_114_chunk.device_id | ||
| -> Gather | ||
| Workers Planned: 2 | ||
| -> Parallel Append |
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This should be GatherMerge above Sort, will be addressed here: #7547
akuzm
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Dec 19, 2024
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| /* | ||
| * Check if this path is parameterized on a compressed | ||
| * column. Ideally those paths wouldn't be generated | ||
| * in the first place but since we create compressed | ||
| * EquivalenceMembers for all EquivalenceClasses these | ||
| * Paths can happen and will fail at execution since | ||
| * the left and right side of the expression are not | ||
| * compatible. Therefore we skip any Path that is | ||
| * parameterized on a compressed column here. | ||
| */ |
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I think I fixed this some time ago, we shouldn't be creating EquivalenceMembers on compressed columns of compressed chunk table anymore because they don't make sense anyway. Removed this check and the tests for older issues still pass.
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The unsorted paths are better for hash aggregation, but currently if we're doing aggregation and we can push down the sort, we are only going to add sorted paths.
Fixes #6836
Fixes #7084