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| author | Richard Guo <rguo@postgresql.org> | 2025-10-08 17:01:48 +0900 |
|---|---|---|
| committer | Richard Guo <rguo@postgresql.org> | 2025-10-08 17:01:48 +0900 |
| commit | 185e304263347d0979832f7a08a812872d136b18 (patch) | |
| tree | df30e7d07467f9e39ba13a2d12b4497ee71b9d20 /src/backend/optimizer/util/relnode.c | |
| parent | 138da727a174219da2d408382e50f8628f1fa38f (diff) | |
Allow negative aggtransspace to indicate unbounded state size
This patch reuses the existing aggtransspace in pg_aggregate to
signal that an aggregate's transition state can grow unboundedly. If
aggtransspace is set to a negative value, it now indicates that the
transition state may consume unpredictable or large amounts of memory,
such as in aggregates like array_agg or string_agg that accumulate
input rows.
This information can be used by the planner to avoid applying
memory-sensitive optimizations (e.g., eager aggregation) when there is
a risk of excessive memory usage during partial aggregation.
Bump catalog version.
Per idea from Robert Haas, though applied differently than originally
suggested.
Discussion: https://postgr.es/m/CA+TgmoYbkvYwLa+1vOP7RDY7kO2=A7rppoPusoRXe44VDOGBPg@mail.gmail.com
Diffstat (limited to 'src/backend/optimizer/util/relnode.c')
0 files changed, 0 insertions, 0 deletions