diff options
| -rw-r--r-- | src/backend/optimizer/prep/prepunion.c | 122 |
1 files changed, 92 insertions, 30 deletions
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c index 888edf578f0..03c06b65da7 100644 --- a/src/backend/optimizer/prep/prepunion.c +++ b/src/backend/optimizer/prep/prepunion.c @@ -14,7 +14,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.68 2001/10/28 06:25:46 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.69 2001/11/12 20:04:20 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -63,6 +63,7 @@ static List *generate_setop_tlist(List *colTypes, int flag, bool hack_constants, List *input_tlist, List *refnames_tlist); +static void merge_tlist_typmods(List *tlist, List *planlist); static bool tlist_same_datatypes(List *tlist, List *colTypes, bool junkOK); static Node *adjust_inherited_attrs_mutator(Node *node, adjust_inherited_attrs_context *context); @@ -204,6 +205,7 @@ generate_union_plan(SetOperationStmt *op, Query *parse, List *refnames_tlist) { List *planlist; + List *tlist; Plan *plan; /* @@ -218,18 +220,21 @@ generate_union_plan(SetOperationStmt *op, Query *parse, op, refnames_tlist)); /* - * Append the child results together. + * Generate tlist for Append plan node. * * The tlist for an Append plan isn't important as far as the Append is * concerned, but we must make it look real anyway for the benefit of * the next plan level up. */ - plan = (Plan *) - make_append(planlist, - false, - generate_setop_tlist(op->colTypes, -1, false, + tlist = generate_setop_tlist(op->colTypes, -1, false, ((Plan *) lfirst(planlist))->targetlist, - refnames_tlist)); + refnames_tlist); + merge_tlist_typmods(tlist, planlist); + + /* + * Append the child results together. + */ + plan = (Plan *) make_append(planlist, false, tlist); /* * For UNION ALL, we just need the Append plan. For UNION, need to @@ -237,10 +242,9 @@ generate_union_plan(SetOperationStmt *op, Query *parse, */ if (!op->all) { - List *tlist, - *sortList; + List *sortList; - tlist = new_unsorted_tlist(plan->targetlist); + tlist = new_unsorted_tlist(tlist); sortList = addAllTargetsToSortList(NIL, tlist); plan = make_sortplan(parse, tlist, plan, sortList); plan = (Plan *) make_unique(tlist, plan, copyObject(sortList)); @@ -259,7 +263,8 @@ generate_nonunion_plan(SetOperationStmt *op, Query *parse, *rplan, *plan; List *tlist, - *sortList; + *sortList, + *planlist; SetOpCmd cmd; /* Recurse on children, ensuring their outputs are marked */ @@ -269,9 +274,10 @@ generate_nonunion_plan(SetOperationStmt *op, Query *parse, rplan = recurse_set_operations(op->rarg, parse, op->colTypes, false, 1, refnames_tlist); + planlist = makeList2(lplan, rplan); /* - * Append the child results together. + * Generate tlist for Append plan node. * * The tlist for an Append plan isn't important as far as the Append is * concerned, but we must make it look real anyway for the benefit of @@ -279,18 +285,21 @@ generate_nonunion_plan(SetOperationStmt *op, Query *parse, * flag column is shown as a variable not a constant, else setrefs.c * will get confused. */ - plan = (Plan *) - make_append(makeList2(lplan, rplan), - false, - generate_setop_tlist(op->colTypes, 2, false, - lplan->targetlist, - refnames_tlist)); + tlist = generate_setop_tlist(op->colTypes, 2, false, + lplan->targetlist, + refnames_tlist); + merge_tlist_typmods(tlist, planlist); + + /* + * Append the child results together. + */ + plan = (Plan *) make_append(planlist, false, tlist); /* * Sort the child results, then add a SetOp plan node to generate the * correct output. */ - tlist = new_unsorted_tlist(plan->targetlist); + tlist = new_unsorted_tlist(tlist); sortList = addAllTargetsToSortList(NIL, tlist); plan = make_sortplan(parse, tlist, plan, sortList); switch (op->op) @@ -332,9 +341,11 @@ recurse_union_children(Node *setOp, Query *parse, { /* Same UNION, so fold children into parent's subplan list */ return nconc(recurse_union_children(op->larg, parse, - top_union, refnames_tlist), + top_union, + refnames_tlist), recurse_union_children(op->rarg, parse, - top_union, refnames_tlist)); + top_union, + refnames_tlist)); } } @@ -380,6 +391,7 @@ generate_setop_tlist(List *colTypes, int flag, Oid colType = (Oid) lfirsti(i); TargetEntry *inputtle = (TargetEntry *) lfirst(input_tlist); TargetEntry *reftle = (TargetEntry *) lfirst(refnames_tlist); + int32 colTypmod; Assert(inputtle->resdom->resno == resno); Assert(reftle->resdom->resno == resno); @@ -399,11 +411,6 @@ generate_setop_tlist(List *colTypes, int flag, * subquery-scan plans; we don't want phony constants appearing in * the output tlists of upper-level nodes! */ - resdom = makeResdom((AttrNumber) resno++, - colType, - -1, - pstrdup(reftle->resdom->resname), - false); if (hack_constants && inputtle->expr && IsA(inputtle->expr, Const)) expr = inputtle->expr; else @@ -412,10 +419,24 @@ generate_setop_tlist(List *colTypes, int flag, inputtle->resdom->restype, inputtle->resdom->restypmod, 0); - expr = coerce_to_common_type(NULL, - expr, - colType, - "UNION/INTERSECT/EXCEPT"); + if (inputtle->resdom->restype == colType) + { + /* no coercion needed, and believe the input typmod */ + colTypmod = inputtle->resdom->restypmod; + } + else + { + expr = coerce_to_common_type(NULL, + expr, + colType, + "UNION/INTERSECT/EXCEPT"); + colTypmod = -1; + } + resdom = makeResdom((AttrNumber) resno++, + colType, + colTypmod, + pstrdup(reftle->resdom->resname), + false); tlist = lappend(tlist, makeTargetEntry(resdom, expr)); input_tlist = lnext(input_tlist); refnames_tlist = lnext(refnames_tlist); @@ -456,6 +477,47 @@ generate_setop_tlist(List *colTypes, int flag, } /* + * Merge typmods of a list of set-operation subplans. + * + * If the inputs all agree on type and typmod of a particular column, + * use that typmod; else use -1. We assume the result tlist has been + * initialized with the types and typmods of the first input subplan. + */ +static void +merge_tlist_typmods(List *tlist, List *planlist) +{ + List *planl; + + foreach(planl, planlist) + { + Plan *subplan = (Plan *) lfirst(planl); + List *subtlist = subplan->targetlist; + List *restlist; + + foreach(restlist, tlist) + { + TargetEntry *restle = (TargetEntry *) lfirst(restlist); + TargetEntry *subtle; + + if (restle->resdom->resjunk) + continue; + Assert(subtlist != NIL); + subtle = (TargetEntry *) lfirst(subtlist); + while (subtle->resdom->resjunk) + { + subtlist = lnext(subtlist); + Assert(subtlist != NIL); + subtle = (TargetEntry *) lfirst(subtlist); + } + if (restle->resdom->restype != subtle->resdom->restype || + restle->resdom->restypmod != subtle->resdom->restypmod) + restle->resdom->restypmod = -1; + subtlist = lnext(subtlist); + } + } +} + +/* * Does tlist have same datatypes as requested colTypes? * * Resjunk columns are ignored if junkOK is true; otherwise presence of |