diff options
| -rw-r--r-- | src/backend/optimizer/prep/prepunion.c | 44 |
1 files changed, 33 insertions, 11 deletions
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c index 764fe1836c6..dbbe004aef2 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 1.65 2001/06/05 05:26:04 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.66 2001/08/14 17:12:57 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -275,12 +275,14 @@ generate_nonunion_plan(SetOperationStmt *op, Query *parse, * * 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. + * the next plan level up. In fact, it has to be real enough that the + * 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, 0, false, + generate_setop_tlist(op->colTypes, 2, false, lplan->targetlist, refnames_tlist)); @@ -353,6 +355,13 @@ recurse_union_children(Node *setOp, Query *parse, /* * Generate targetlist for a set-operation plan node + * + * colTypes: column datatypes for non-junk columns + * flag: -1 if no flag column needed, 0 or 1 to create a const flag column, + * 2 to create a variable flag column + * 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 */ static List * generate_setop_tlist(List *colTypes, int flag, @@ -414,19 +423,32 @@ generate_setop_tlist(List *colTypes, int flag, if (flag >= 0) { - /* Add a resjunk column yielding specified flag value */ + /* Add a resjunk flag column */ resdom = makeResdom((AttrNumber) resno++, INT4OID, -1, pstrdup("flag"), true); - expr = (Node *) makeConst(INT4OID, - sizeof(int4), - Int32GetDatum(flag), - false, - true, - false, - false); + if (flag <= 1) + { + /* flag value is the given constant */ + expr = (Node *) makeConst(INT4OID, + sizeof(int4), + Int32GetDatum(flag), + false, + true, + false, + false); + } + else + { + /* flag value is being copied up from subplan */ + expr = (Node *) makeVar(0, + resdom->resno, + INT4OID, + -1, + 0); + } tlist = lappend(tlist, makeTargetEntry(resdom, expr)); } |