diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/optimizer/plan/setrefs.c | 23 | ||||
| -rw-r--r-- | src/test/regress/expected/inherit.out | 2 |
2 files changed, 24 insertions, 1 deletions
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c index d10a98396c7..d91bc3b30de 100644 --- a/src/backend/optimizer/plan/setrefs.c +++ b/src/backend/optimizer/plan/setrefs.c @@ -1823,6 +1823,19 @@ set_dummy_tlist_references(Plan *plan, int rtoffset) Var *oldvar = (Var *) tle->expr; Var *newvar; + /* + * As in search_indexed_tlist_for_non_var(), we prefer to keep Consts + * as Consts, not Vars referencing Consts. Here, there's no speed + * advantage to be had, but it makes EXPLAIN output look cleaner, and + * again it avoids confusing the executor. + */ + if (IsA(oldvar, Const)) + { + /* just reuse the existing TLE node */ + output_targetlist = lappend(output_targetlist, tle); + continue; + } + newvar = makeVar(OUTER_VAR, tle->resno, exprType((Node *) oldvar), @@ -2010,6 +2023,16 @@ search_indexed_tlist_for_non_var(Node *node, { TargetEntry *tle; + /* + * If it's a simple Const, replacing it with a Var is silly, even if there + * happens to be an identical Const below; a Var is more expensive to + * execute than a Const. What's more, replacing it could confuse some + * places in the executor that expect to see simple Consts for, eg, + * dropped columns. + */ + if (IsA(node, Const)) + return NULL; + tle = tlist_member(node, itlist->tlist); if (tle) { diff --git a/src/test/regress/expected/inherit.out b/src/test/regress/expected/inherit.out index df7cba6614d..79e9969d574 100644 --- a/src/test/regress/expected/inherit.out +++ b/src/test/regress/expected/inherit.out @@ -1426,7 +1426,7 @@ ORDER BY thousand, tenthous; Sort Key: tenk1.thousand, tenk1.tenthous -> Index Only Scan using tenk1_thous_tenthous on tenk1 -> Sort - Sort Key: (42), (42) + Sort Key: 42, 42 -> Index Only Scan using tenk1_hundred on tenk1 tenk1_1 (6 rows) |