ORCA: fall back to Postgres planner for KNN ORDER BY queries#1653
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yjhjstz merged 2 commits intoapache:mainfrom Apr 16, 2026
Merged
ORCA: fall back to Postgres planner for KNN ORDER BY queries#1653yjhjstz merged 2 commits intoapache:mainfrom
yjhjstz merged 2 commits intoapache:mainfrom
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my-ship-it
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Apr 1, 2026
my-ship-it
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Apr 1, 2026
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will try to take a look soon. Changes looks sane |
ORCA is unaware of amcanorderbyop, so it plans "ORDER BY col <-> val" queries with a full Seq Scan + Sort instead of a native KNN ordered index scan. Detect this pattern by checking whether any ORDER BY target is an operator with amoppurpose = AMOP_ORDER in pg_amop and at least one direct Var argument, then raise ExmiQuery2DXLUnsupportedFeature to hand the query off to the Postgres planner, which generates an efficient Index Only Scan with native KNN ordering. Queries where the ordering operator's arguments are entirely computed expressions (e.g. circle(col,1) <-> point(0,0)) are excluded from the fallback to avoid lossy-distance errors in index-only scans.
leborchuk
approved these changes
Apr 10, 2026
reshke
approved these changes
Apr 14, 2026
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ORCA is unaware of amcanorderbyop, so it plans "ORDER BY col <-> val"
queries with a full Seq Scan + Sort instead of a native KNN ordered
index scan. Detect this pattern by checking whether any ORDER BY
target is an operator with amoppurpose = AMOP_ORDER in pg_amop and at
least one direct Var argument, then raise ExmiQuery2DXLUnsupportedFeature
to hand the query off to the Postgres planner, which generates an
efficient Index Only Scan with native KNN ordering.
Queries where the ordering operator's arguments are entirely computed
expressions (e.g. circle(col,1) <-> point(0,0)) are excluded from the
fallback to avoid lossy-distance errors in index-only scans.
Fixes #ISSUE_Number
What does this PR do?
Type of Change
Breaking Changes
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make installcheckmake -C src/test installcheck-cbdb-parallelImpact
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