diff options
Diffstat (limited to 'src/backend/executor/nodeSubplan.c')
| -rw-r--r-- | src/backend/executor/nodeSubplan.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/src/backend/executor/nodeSubplan.c b/src/backend/executor/nodeSubplan.c index aee6911e5e4..933dcc83425 100644 --- a/src/backend/executor/nodeSubplan.c +++ b/src/backend/executor/nodeSubplan.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/executor/nodeSubplan.c,v 1.27 2000/08/24 03:29:03 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/executor/nodeSubplan.c,v 1.28 2000/10/05 19:11:26 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -328,7 +328,14 @@ ExecInitSubPlan(SubPlan *node, EState *estate, Plan *parent) /* ---------------------------------------------------------------- * ExecSetParamPlan * - * Executes plan of node and sets parameters. + * Executes an InitPlan subplan and sets its output parameters. + * + * This is called from ExecEvalParam() when the value of a PARAM_EXEC + * parameter is requested and the param's execPlan field is set (indicating + * that the param has not yet been evaluated). This allows lazy evaluation + * of initplans: we don't run the subplan until/unless we need its output. + * Note that this routine MUST clear the execPlan fields of the plan's + * output parameters after evaluating them! * ---------------------------------------------------------------- */ void @@ -424,13 +431,13 @@ ExecSetParamPlan(SubPlan *node, ExprContext *econtext) } } - MemoryContextSwitchTo(oldcontext); - if (plan->extParam == NULL) /* un-correlated ... */ { ExecEndNode(plan, plan); node->needShutdown = false; } + + MemoryContextSwitchTo(oldcontext); } /* ---------------------------------------------------------------- @@ -470,6 +477,9 @@ ExecReScanSetParamPlan(SubPlan *node, Plan *parent) * node->plan->chgParam is not NULL... ExecReScan (plan, NULL, plan); */ + /* + * Mark this subplan's output parameters as needing recalculation + */ foreach(lst, node->setParam) { ParamExecData *prm = &(plan->state->es_param_exec_vals[lfirsti(lst)]); |