diff options
Diffstat (limited to 'src/backend/optimizer/prep/prepunion.c')
| -rw-r--r-- | src/backend/optimizer/prep/prepunion.c | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c index f004fad1d92..2214920dea4 100644 --- a/src/backend/optimizer/prep/prepunion.c +++ b/src/backend/optimizer/prep/prepunion.c @@ -78,7 +78,8 @@ static List *generate_setop_tlist(List *colTypes, List *colCollations, Index varno, bool hack_constants, List *input_tlist, - List *refnames_tlist); + List *refnames_tlist, + bool *trivial_tlist); static List *generate_append_tlist(List *colTypes, List *colCollations, bool flag, List *input_tlists, @@ -226,6 +227,7 @@ recurse_set_operations(Node *setOp, PlannerInfo *root, Path *subpath; Path *path; List *tlist; + bool trivial_tlist; Assert(subquery != NULL); @@ -254,7 +256,8 @@ recurse_set_operations(Node *setOp, PlannerInfo *root, rtr->rtindex, true, subroot->processed_tlist, - refnames_tlist); + refnames_tlist, + &trivial_tlist); rel->reltarget = create_pathtarget(root, tlist); /* Return the fully-fledged tlist to caller, too */ @@ -291,6 +294,7 @@ recurse_set_operations(Node *setOp, PlannerInfo *root, * soon too, likely.) */ path = (Path *) create_subqueryscan_path(root, rel, subpath, + trivial_tlist, NIL, NULL); add_path(rel, path); @@ -309,6 +313,7 @@ recurse_set_operations(Node *setOp, PlannerInfo *root, partial_subpath = linitial(final_rel->partial_pathlist); partial_path = (Path *) create_subqueryscan_path(root, rel, partial_subpath, + trivial_tlist, NIL, NULL); add_partial_path(rel, partial_path); } @@ -376,6 +381,7 @@ recurse_set_operations(Node *setOp, PlannerInfo *root, !tlist_same_collations(*pTargetList, colCollations, junkOK)) { PathTarget *target; + bool trivial_tlist; ListCell *lc; *pTargetList = generate_setop_tlist(colTypes, colCollations, @@ -383,7 +389,8 @@ recurse_set_operations(Node *setOp, PlannerInfo *root, 0, false, *pTargetList, - refnames_tlist); + refnames_tlist, + &trivial_tlist); target = create_pathtarget(root, *pTargetList); /* Apply projection to each path */ @@ -1117,6 +1124,7 @@ choose_hashed_setop(PlannerInfo *root, List *groupClauses, * hack_constants: true to copy up constants (see comments in code) * input_tlist: targetlist of this node's input node * refnames_tlist: targetlist to take column names from + * trivial_tlist: output parameter, set to true if targetlist is trivial */ static List * generate_setop_tlist(List *colTypes, List *colCollations, @@ -1124,7 +1132,8 @@ generate_setop_tlist(List *colTypes, List *colCollations, Index varno, bool hack_constants, List *input_tlist, - List *refnames_tlist) + List *refnames_tlist, + bool *trivial_tlist) { List *tlist = NIL; int resno = 1; @@ -1135,6 +1144,8 @@ generate_setop_tlist(List *colTypes, List *colCollations, TargetEntry *tle; Node *expr; + *trivial_tlist = true; /* until proven differently */ + forfour(ctlc, colTypes, cclc, colCollations, itlc, input_tlist, rtlc, refnames_tlist) { @@ -1160,6 +1171,9 @@ generate_setop_tlist(List *colTypes, List *colCollations, * this only at the first level of subquery-scan plans; we don't want * phony constants appearing in the output tlists of upper-level * nodes! + * + * Note that copying a constant doesn't in itself require us to mark + * the tlist nontrivial; see trivial_subqueryscan() in setrefs.c. */ if (hack_constants && inputtle->expr && IsA(inputtle->expr, Const)) expr = (Node *) inputtle->expr; @@ -1185,6 +1199,7 @@ generate_setop_tlist(List *colTypes, List *colCollations, expr, colType, "UNION/INTERSECT/EXCEPT"); + *trivial_tlist = false; /* the coercion makes it not trivial */ } /* @@ -1199,9 +1214,12 @@ generate_setop_tlist(List *colTypes, List *colCollations, * will reach the executor without any further processing. */ if (exprCollation(expr) != colColl) + { expr = applyRelabelType(expr, exprType(expr), exprTypmod(expr), colColl, COERCE_IMPLICIT_CAST, -1, false); + *trivial_tlist = false; /* the relabel makes it not trivial */ + } tle = makeTargetEntry((Expr *) expr, (AttrNumber) resno++, @@ -1234,6 +1252,7 @@ generate_setop_tlist(List *colTypes, List *colCollations, pstrdup("flag"), true); tlist = lappend(tlist, tle); + *trivial_tlist = false; /* the extra entry makes it not trivial */ } return tlist; |