mirror of
https://git.postgresql.org/git/postgresql.git
synced 2026-02-07 12:37:34 +08:00
f36e82072c
The planner is in fact willing to use hash aggregation when work_mem is not set high enough for everything to fit in memory. This has been the case since commit 1f39bce0, which added disk-based hash aggregation. There are a few remaining cases in which hash aggregation is avoided as a matter of policy when the planner surmises that spilling will be necessary. For example, callers of choose_hashed_setop() still conservatively avoid hash aggregation when spilling is anticipated. That doesn't seem like a good enough reason to mention hash aggregation in this context. Backpatch: 13-, where disk-based hash aggregation was introduced.