Tom Lane wrote:
Hm, the "Assert(rte->subquery != NULL)" doesn't seem right ...
couldn't there be non-RTE_SUBQUERY rtes in the child? I think the
original coding was guaranteed to visit only subquery-type RTEs
but I'm much less convinced about this one. It might
be better to say
if (rte->rtekind == RTE_SUBQUERY)
IncrementVarSublevelsUp(...);
Or maybe it's okay; I'm too lazy to recheck the representation of
UNION ALL right now.
Oh, indeed it's not okay. The original UNION ALL view is a prime example
of that. I didn't notice because I was testing without assertions.
Hmm, do we need the copyObject() call for non-subquery RTEs? I'm
guessing no, because they're not modified.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
Index: src/backend/optimizer/prep/prepjointree.c
===================================================================
RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/backend/optimizer/prep/prepjointree.c,v
retrieving revision 1.44
diff -c -r1.44 prepjointree.c
*** src/backend/optimizer/prep/prepjointree.c 4 Oct 2006 00:29:54 -0000 1.44
--- src/backend/optimizer/prep/prepjointree.c 13 Aug 2008 06:41:49 -0000
***************
*** 46,52 ****
static Node *pull_up_simple_union_all(PlannerInfo *root, Node *jtnode,
RangeTblEntry *rte);
static void pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root,
! int parentRTindex, Query *setOpQuery);
static void make_setop_translation_lists(Query *query,
Index newvarno,
List **col_mappings, List **translated_vars);
--- 46,52 ----
static Node *pull_up_simple_union_all(PlannerInfo *root, Node *jtnode,
RangeTblEntry *rte);
static void pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root,
! int parentRTindex, Query *setOpQuery, int childRToffset);
static void make_setop_translation_lists(Query *query,
Index newvarno,
List **col_mappings, List **translated_vars);
***************
*** 477,490 ****
{
int varno = ((RangeTblRef *) jtnode)->rtindex;
Query *subquery = rte->subquery;
/*
! * Recursively scan the subquery's setOperations tree and copy the leaf
! * subqueries into the parent rangetable. Add AppendRelInfo nodes for
! * them to the parent's append_rel_list, too.
*/
Assert(subquery->setOperations);
! pull_up_union_leaf_queries(subquery->setOperations, root, varno, subquery);
/*
* Mark the parent as an append relation.
--- 477,520 ----
{
int varno = ((RangeTblRef *) jtnode)->rtindex;
Query *subquery = rte->subquery;
+ ListCell *l;
+ int rtoffset;
/*
! * Append the subquery rtable entries to upper query.
! */
! rtoffset = list_length(root->parse->rtable);
! foreach(l, subquery->rtable)
! {
! RangeTblEntry *rte = (RangeTblEntry *) lfirst(l);
!
! /*
! * Upper-level vars in subquery are now one level closer to their
! * parent than before. We don't have to worry about offsetting
! * varnos, though, because any such vars must refer to stuff above the
! * level of the query we are pulling into.
! */
! if (rte->subquery)
! {
! /* Make a modifiable copy of the child RTE and contained query. */
! rte = copyObject(rte);
! IncrementVarSublevelsUp((Node *) rte->subquery, -1, 1);
! }
!
! /*
! * Attach child RTE to parent rtable.
! */
! root->parse->rtable = lappend(root->parse->rtable, rte);
! }
!
! /*
! * Recursively scan the subquery's setOperations tree and add
! * AppendRelInfo nodes for leaf subqueries to the parent's
! * append_rel_list.
*/
Assert(subquery->setOperations);
! pull_up_union_leaf_queries(subquery->setOperations, root, varno, subquery,
! rtoffset);
/*
* Mark the parent as an append relation.
***************
*** 500,540 ****
* Note that setOpQuery is the Query containing the setOp node, whose rtable
* is where to look up the RTE if setOp is a RangeTblRef. This is *not* the
* same as root->parse, which is the top-level Query we are pulling up into.
* parentRTindex is the appendrel parent's index in root->parse->rtable.
*/
static void
pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root, int parentRTindex,
! Query *setOpQuery)
{
if (IsA(setOp, RangeTblRef))
{
RangeTblRef *rtr = (RangeTblRef *) setOp;
- RangeTblEntry *rte = rt_fetch(rtr->rtindex, setOpQuery->rtable);
- Query *subquery;
int childRTindex;
AppendRelInfo *appinfo;
- Query *parse = root->parse;
-
- /*
- * Make a modifiable copy of the child RTE and contained query.
- */
- rte = copyObject(rte);
- subquery = rte->subquery;
- Assert(subquery != NULL);
/*
! * Upper-level vars in subquery are now one level closer to their
! * parent than before. We don't have to worry about offsetting
! * varnos, though, because any such vars must refer to stuff above the
! * level of the query we are pulling into.
! */
! IncrementVarSublevelsUp((Node *) subquery, -1, 1);
!
! /*
! * Attach child RTE to parent rtable.
*/
! parse->rtable = lappend(parse->rtable, rte);
! childRTindex = list_length(parse->rtable);
/*
* Build a suitable AppendRelInfo, and attach to parent's list.
--- 530,555 ----
* Note that setOpQuery is the Query containing the setOp node, whose rtable
* is where to look up the RTE if setOp is a RangeTblRef. This is *not* the
* same as root->parse, which is the top-level Query we are pulling up into.
+ *
* parentRTindex is the appendrel parent's index in root->parse->rtable.
+ *
+ * The child RTEs have already been copied to the parent. childRToffset
+ * tells us where in the parent's range table they were copied.
*/
static void
pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root, int parentRTindex,
! Query *setOpQuery, int childRToffset)
{
if (IsA(setOp, RangeTblRef))
{
RangeTblRef *rtr = (RangeTblRef *) setOp;
int childRTindex;
AppendRelInfo *appinfo;
/*
! * Calculate the index in the parent's range table
*/
! childRTindex = childRToffset + rtr->rtindex;
/*
* Build a suitable AppendRelInfo, and attach to parent's list.
***************
*** 566,573 ****
SetOperationStmt *op = (SetOperationStmt *) setOp;
/* Recurse to reach leaf queries */
! pull_up_union_leaf_queries(op->larg, root, parentRTindex, setOpQuery);
! pull_up_union_leaf_queries(op->rarg, root, parentRTindex, setOpQuery);
}
else
{
--- 581,590 ----
SetOperationStmt *op = (SetOperationStmt *) setOp;
/* Recurse to reach leaf queries */
! pull_up_union_leaf_queries(op->larg, root, parentRTindex, setOpQuery,
! childRToffset);
! pull_up_union_leaf_queries(op->rarg, root, parentRTindex, setOpQuery,
! childRToffset);
}
else
{
--
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