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Allow UNION/UNION ALL in subselects.

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This commit is contained in:
Bruce Momjian
1998-07-15 22:16:21 +00:00
parent 2077ce123b
commit c1f1a2e03a
4 changed files with 33 additions and 5 deletions
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27
src/backend/executor/nodeAppend.c
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@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/nodeAppend.c,v 1.13 1998/07/15 14:54:30 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/executor/nodeAppend.c,v 1.14 1998/07/15 22:16:18 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -15,6 +15,7 @@
* ExecInitAppend - initialize the append node
* ExecProcAppend - retrieve the next tuple from the node
* ExecEndAppend - shut down the append node
* ExecReScanAppend - rescan the append node
*
* NOTES
* Each append node contains a list of one or more subplans which
@ -34,7 +35,7 @@
* nil nil ... ... ...
* subplans
*
* Append nodes are currently used to unions, and to support inheritance
* Append nodes are currently used for unions, and to support inheritance
* queries, where several relations need to be scanned.
* For example, in our standard person/student/employee/student-emp
* example, where student and employee inherit from person
@ -500,3 +501,25 @@ ExecEndAppend(Append *node)
* appendstate->as_junkfilter_list here
*/
}
void
ExecReScanAppend(Append *node, ExprContext *exprCtxt, Plan *parent)
{
AppendState *appendstate = node->appendstate;
int nplans = length(node->appendplans);
int i;
for (i = 0; i < nplans; i++)
{
Plan *rescanNode;
appendstate->as_whichplan = i;
rescanNode = (Plan *) nth(i, node->appendplans);
if (rescanNode->chgParam == NULL)
{
exec_append_initialize_next(node);
ExecReScan((Plan *)rescanNode, exprCtxt, (Plan *) node);
}
}
appendstate->as_whichplan = 0;
exec_append_initialize_next(node);
}