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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2022-03-31 14:29:24 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2022-03-31 14:29:48 -0400 |
| commit | f3dd9fe1dd9254680591aa8d9891b90b8d735b2a (patch) | |
| tree | 1ea194c6b7eb3da25d1c5298b3f6f783127bb4e5 /contrib/postgres_fdw/postgres_fdw.h | |
| parent | 28bdfa2adfc6afe4121614b500bfcb27b7c6b94c (diff) | |
| download | postgresql-f3dd9fe1dd9254680591aa8d9891b90b8d735b2a.tar.gz postgresql-f3dd9fe1dd9254680591aa8d9891b90b8d735b2a.zip | |
Fix postgres_fdw to check shippability of sort clauses properly.
postgres_fdw would push ORDER BY clauses to the remote side without
verifying that the sort operator is safe to ship. Moreover, it failed
to print a suitable USING clause if the sort operator isn't default
for the sort expression's type. The net result of this is that the
remote sort might not have anywhere near the semantics we expect,
which'd be disastrous for locally-performed merge joins in particular.
We addressed similar issues in the context of ORDER BY within an
aggregate function call in commit 7012b132d, but failed to notice
that query-level ORDER BY was broken. Thus, much of the necessary
logic already existed, but it requires refactoring to be usable
in both cases.
Back-patch to all supported branches. In HEAD only, remove the
core code's copy of find_em_expr_for_rel, which is no longer used
and really should never have been pushed into equivclass.c in the
first place.
Ronan Dunklau, per report from David Rowley;
reviews by David Rowley, Ranier Vilela, and myself
Discussion: https://postgr.es/m/CAApHDvr4OeC2DBVY--zVP83-K=bYrTD7F8SZDhN4g+pj2f2S-A@mail.gmail.com
Diffstat (limited to 'contrib/postgres_fdw/postgres_fdw.h')
| -rw-r--r-- | contrib/postgres_fdw/postgres_fdw.h | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/contrib/postgres_fdw/postgres_fdw.h b/contrib/postgres_fdw/postgres_fdw.h index 8ae79e97e44..21f2b20ce8d 100644 --- a/contrib/postgres_fdw/postgres_fdw.h +++ b/contrib/postgres_fdw/postgres_fdw.h @@ -173,6 +173,9 @@ extern bool is_foreign_expr(PlannerInfo *root, extern bool is_foreign_param(PlannerInfo *root, RelOptInfo *baserel, Expr *expr); +extern bool is_foreign_pathkey(PlannerInfo *root, + RelOptInfo *baserel, + PathKey *pathkey); extern void deparseInsertSql(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, List *targetAttrs, bool doNothing, @@ -215,10 +218,12 @@ extern void deparseTruncateSql(StringInfo buf, DropBehavior behavior, bool restart_seqs); extern void deparseStringLiteral(StringInfo buf, const char *val); -extern Expr *find_em_expr_for_rel(EquivalenceClass *ec, RelOptInfo *rel); -extern Expr *find_em_expr_for_input_target(PlannerInfo *root, - EquivalenceClass *ec, - PathTarget *target); +extern EquivalenceMember *find_em_for_rel(PlannerInfo *root, + EquivalenceClass *ec, + RelOptInfo *rel); +extern EquivalenceMember *find_em_for_rel_target(PlannerInfo *root, + EquivalenceClass *ec, + RelOptInfo *rel); extern List *build_tlist_to_deparse(RelOptInfo *foreignrel); extern void deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel, List *tlist, |