Ensure set-returning functions in the targetlist of a plan node will be

shut down cleanly if the plan node is ReScanned before the SRFs are run
to completion.  This fixes the problem for SQL-language functions, but
still need work on functions using the SRF_XXX() macros.
This commit is contained in:
Tom Lane 2003-12-18 20:21:53 +00:00
parent 716a3d6cff
commit dc254c8674
3 changed files with 41 additions and 9 deletions

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@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Header: /cvsroot/pgsql/src/backend/executor/execAmi.c,v 1.75 2003/08/08 21:41:34 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/executor/execAmi.c,v 1.75.4.1 2003/12/18 20:21:53 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -39,13 +39,20 @@
#include "executor/nodeUnique.h"
/* ----------------------------------------------------------------
* ExecReScan
/*
* ExecReScan
* Reset a plan node so that its output can be re-scanned.
*
* takes the new expression context as an argument, so that
* index scans needn't have their scan keys updated separately
* - marcel 09/20/94
* ----------------------------------------------------------------
* Note that if the plan node has parameters that have changed value,
* the output might be different from last time.
*
* The second parameter is currently only used to pass a NestLoop plan's
* econtext down to its inner child plan, in case that is an indexscan that
* needs access to variables of the current outer tuple. (The handling of
* this parameter is currently pretty inconsistent: some callers pass NULL
* and some pass down their parent's value; so don't rely on it in other
* situations. It'd probably be better to remove the whole thing and use
* the generalized parameter mechanism instead.)
*/
void
ExecReScan(PlanState *node, ExprContext *exprCtxt)
@ -85,6 +92,11 @@ ExecReScan(PlanState *node, ExprContext *exprCtxt)
UpdateChangedParamSet(node->righttree, node->chgParam);
}
/* Shut down any SRFs in the plan node's targetlist */
if (node->ps_ExprContext)
ReScanExprContext(node->ps_ExprContext);
/* And do node-type-specific processing */
switch (nodeTag(node))
{
case T_ResultState:

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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/execUtils.c,v 1.106 2003/10/01 21:30:52 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/executor/execUtils.c,v 1.106.2.1 2003/12/18 20:21:53 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -18,6 +18,7 @@
* FreeExecutorState
* CreateExprContext
* FreeExprContext
* ReScanExprContext
*
* ExecAssignExprContext Common code for plan node init routines.
* ExecAssignResultType
@ -352,6 +353,24 @@ FreeExprContext(ExprContext *econtext)
pfree(econtext);
}
/*
* ReScanExprContext
*
* Reset an expression context in preparation for a rescan of its
* plan node. This requires calling any registered shutdown callbacks,
* since any partially complete set-returning-functions must be canceled.
*
* Note we make no assumption about the caller's memory context.
*/
void
ReScanExprContext(ExprContext *econtext)
{
/* Call any registered callbacks */
ShutdownExprContext(econtext);
/* And clean up the memory used */
MemoryContextReset(econtext->ecxt_per_tuple_memory);
}
/*
* Build a per-output-tuple ExprContext for an EState.
*

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@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: executor.h,v 1.102 2003/10/01 21:30:52 tgl Exp $
* $Id: executor.h,v 1.102.2.1 2003/12/18 20:21:53 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -201,6 +201,7 @@ extern EState *CreateExecutorState(void);
extern void FreeExecutorState(EState *estate);
extern ExprContext *CreateExprContext(EState *estate);
extern void FreeExprContext(ExprContext *econtext);
extern void ReScanExprContext(ExprContext *econtext);
#define ResetExprContext(econtext) \
MemoryContextReset((econtext)->ecxt_per_tuple_memory)