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| author | Tomas Vondra <tomas.vondra@postgresql.org> | 2020-12-21 18:29:46 +0100 |
|---|---|---|
| committer | Tomas Vondra <tomas.vondra@postgresql.org> | 2020-12-21 18:29:49 +0100 |
| commit | 86b7cca72d4d0a4e043fac0a2cdd56218ff2f258 (patch) | |
| tree | 43acee2bc25e67f25883383674bd78f64c6f004e /src/include/optimizer/paths.h | |
| parent | f4a3c0b06250ddc8ae09b59b87cf68e9bc0d7ca1 (diff) | |
| download | postgresql-86b7cca72d4d0a4e043fac0a2cdd56218ff2f258.tar.gz | |
Check parallel safety in generate_useful_gather_paths
Commit ebb7ae839d ensured we ignore pathkeys with volatile expressions
when considering adding a sort below a Gather Merge. Turns out we need
to care about parallel safety of the pathkeys too, otherwise we might
try sorting e.g. on results of a correlated subquery (as demonstrated
by a report from Luis Roberto).
Initial investigation by Tom Lane, patch by James Coleman. Backpatch
to 13, where the code was instroduced (as part of Incremental Sort).
Reported-by: Luis Roberto
Author: James Coleman
Reviewed-by: Tomas Vondra
Backpatch-through: 13
Discussion: https://postgr.es/m/622580997.37108180.1604080457319.JavaMail.zimbra%40siscobra.com.br
Discussion: https://postgr.es/m/CAAaqYe8cK3g5CfLC4w7bs=hC0mSksZC=H5M8LSchj5e5OxpTAg@mail.gmail.com
Diffstat (limited to 'src/include/optimizer/paths.h')
| -rw-r--r-- | src/include/optimizer/paths.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/include/optimizer/paths.h b/src/include/optimizer/paths.h index 8a4c6f8b59..bf6c16b804 100644 --- a/src/include/optimizer/paths.h +++ b/src/include/optimizer/paths.h @@ -135,7 +135,10 @@ extern EquivalenceClass *get_eclass_for_sort_expr(PlannerInfo *root, Relids rel, bool create_it); extern Expr *find_em_expr_for_rel(EquivalenceClass *ec, RelOptInfo *rel); -extern Expr *find_em_expr_usable_for_sorting_rel(EquivalenceClass *ec, RelOptInfo *rel); +extern Expr *find_em_expr_usable_for_sorting_rel(PlannerInfo *root, + EquivalenceClass *ec, + RelOptInfo *rel, + bool require_parallel_safe); extern void generate_base_implied_equalities(PlannerInfo *root); extern List *generate_join_implied_equalities(PlannerInfo *root, Relids join_relids, |