Adjust cost model for HashAgg that spills to disk. Tomas Vondra observed that the IO behavior for HashAgg tends to be worse than for Sort. Penalize HashAgg IO costs accordingly.
Also, account for the CPU effort of spilling the tuples and reading them back. Discussion: https://postgr.es/m/20200906212112.nzoy5ytrzjjodpfh@development Reviewed-by: Tomas Vondra Backpatch-through: 13 Branch ------ REL_13_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/b61d048e0d480f4311c62bf3026879c83ba9aaad Modified Files -------------- src/backend/optimizer/path/costsize.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
