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Reimplementation of UNION/INTERSECT/EXCEPT. INTERSECT/EXCEPT now meet the

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SQL92 semantics, including support for ALL option.  All three can be used
in subqueries and views.  DISTINCT and ORDER BY work now in views, too.
This rewrite fixes many problems with cross-datatype UNIONs and INSERT/SELECT
where the SELECT yields different datatypes than the INSERT needs.  I did
that by making UNION subqueries and SELECT in INSERT be treated like
subselects-in-FROM, thereby allowing an extra level of targetlist where the
datatype conversions can be inserted safely.
INITDB NEEDED!
This commit is contained in:
Tom Lane
2000-10-05 19:11:39 +00:00
parent 5292637f52
commit 05e3d0ee86
51 changed files with 2621 additions and 1935 deletions
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55
src/backend/executor/nodeSubqueryscan.c
View File

@ -3,12 +3,16 @@
* nodeSubqueryscan.c
* Support routines for scanning subqueries (subselects in rangetable).
*
* This is just enough different from sublinks (nodeSubplan.c) to mean that
* we need two sets of code. Ought to look at trying to unify the cases.
*
*
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/nodeSubqueryscan.c,v 1.1 2000/09/29 18:21:29 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/executor/nodeSubqueryscan.c,v 1.2 2000/10/05 19:11:26 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -49,9 +53,7 @@ SubqueryNext(SubqueryScan *node)
SubqueryScanState *subquerystate;
EState *estate;
ScanDirection direction;
int execdir;
TupleTableSlot *slot;
Const countOne;
/* ----------------
* get information from the estate and scan state
@ -60,7 +62,6 @@ SubqueryNext(SubqueryScan *node)
estate = node->scan.plan.state;
subquerystate = (SubqueryScanState *) node->scan.scanstate;
direction = estate->es_direction;
execdir = ScanDirectionIsBackward(direction) ? EXEC_BACK : EXEC_FOR;
slot = subquerystate->csstate.css_ScanTupleSlot;
/*
@ -85,25 +86,13 @@ SubqueryNext(SubqueryScan *node)
return (slot);
}
memset(&countOne, 0, sizeof(countOne));
countOne.type = T_Const;
countOne.consttype = INT4OID;
countOne.constlen = sizeof(int4);
countOne.constvalue = Int32GetDatum(1);
countOne.constisnull = false;
countOne.constbyval = true;
countOne.constisset = false;
countOne.constiscast = false;
/* ----------------
* get the next tuple from the sub-query
* ----------------
*/
slot = ExecutorRun(subquerystate->sss_SubQueryDesc,
subquerystate->sss_SubEState,
execdir,
NULL, /* offset */
(Node *) &countOne);
subquerystate->sss_SubEState->es_direction = direction;
slot = ExecProcNode(node->subplan, node->subplan);
subquerystate->csstate.css_ScanTupleSlot = slot;
@ -139,6 +128,7 @@ ExecInitSubqueryScan(SubqueryScan *node, EState *estate, Plan *parent)
{
SubqueryScanState *subquerystate;
RangeTblEntry *rte;
EState *sp_estate;
/* ----------------
* SubqueryScan should not have any "normal" children.
@ -177,18 +167,25 @@ ExecInitSubqueryScan(SubqueryScan *node, EState *estate, Plan *parent)
/* ----------------
* initialize subquery
*
* This should agree with ExecInitSubPlan
* ----------------
*/
rte = rt_fetch(node->scan.scanrelid, estate->es_range_table);
Assert(rte->subquery != NULL);
subquerystate->sss_SubQueryDesc = CreateQueryDesc(rte->subquery,
node->subplan,
None);
subquerystate->sss_SubEState = CreateExecutorState();
sp_estate = CreateExecutorState();
subquerystate->sss_SubEState = sp_estate;
ExecutorStart(subquerystate->sss_SubQueryDesc,
subquerystate->sss_SubEState);
sp_estate->es_range_table = rte->subquery->rtable;
sp_estate->es_param_list_info = estate->es_param_list_info;
sp_estate->es_param_exec_vals = estate->es_param_exec_vals;
sp_estate->es_tupleTable =
ExecCreateTupleTable(ExecCountSlotsNode(node->subplan) + 10);
sp_estate->es_snapshot = estate->es_snapshot;
if (!ExecInitNode(node->subplan, sp_estate, NULL))
return false;
subquerystate->csstate.css_ScanTupleSlot = NULL;
subquerystate->csstate.cstate.cs_TupFromTlist = false;
@ -247,10 +244,9 @@ ExecEndSubqueryScan(SubqueryScan *node)
* close down subquery
* ----------------
*/
ExecutorEnd(subquerystate->sss_SubQueryDesc,
subquerystate->sss_SubEState);
ExecEndNode(node->subplan, node->subplan);
/* XXX we seem to be leaking the querydesc and sub-EState... */
/* XXX we seem to be leaking the sub-EState and tuple table... */
subquerystate->csstate.css_ScanTupleSlot = NULL;
@ -284,6 +280,7 @@ ExecSubqueryReScan(SubqueryScan *node, ExprContext *exprCtxt, Plan *parent)
return;
}
ExecReScan(node->subplan, NULL, NULL);
ExecReScan(node->subplan, NULL, node->subplan);
subquerystate->csstate.css_ScanTupleSlot = NULL;
}