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author | Tom Lane <tgl@sss.pgh.pa.us> | 2006-02-28 04:10:28 +0000 |
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committer | Tom Lane <tgl@sss.pgh.pa.us> | 2006-02-28 04:10:28 +0000 |
commit | 2c0ef9777cce8f97dd01073d962e6aa31722b5ad (patch) | |
tree | bcfa428f69e6013002a79ab29e053bd6c6cbcfa7 /src/backend/executor/nodeNestloop.c | |
parent | 7f4f42fa100872507ca10d8e0f7d923acc266ee8 (diff) | |
download | postgresql-2c0ef9777cce8f97dd01073d962e6aa31722b5ad.tar.gz |
Extend the ExecInitNode API so that plan nodes receive a set of flag
bits indicating which optional capabilities can actually be exercised
at runtime. This will allow Sort and Material nodes, and perhaps later
other nodes, to avoid unnecessary overhead in common cases.
This commit just adds the infrastructure and arranges to pass the correct
flag values down to plan nodes; none of the actual optimizations are here
yet. I'm committing this separately in case anyone wants to measure the
added overhead. (It should be negligible.)
Simon Riggs and Tom Lane
Diffstat (limited to 'src/backend/executor/nodeNestloop.c')
-rw-r--r-- | src/backend/executor/nodeNestloop.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/src/backend/executor/nodeNestloop.c b/src/backend/executor/nodeNestloop.c index e205b218bd..4611a809af 100644 --- a/src/backend/executor/nodeNestloop.c +++ b/src/backend/executor/nodeNestloop.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/nodeNestloop.c,v 1.40 2005/11/22 18:17:10 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/executor/nodeNestloop.c,v 1.41 2006/02/28 04:10:27 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -272,10 +272,13 @@ ExecNestLoop(NestLoopState *node) * ---------------------------------------------------------------- */ NestLoopState * -ExecInitNestLoop(NestLoop *node, EState *estate) +ExecInitNestLoop(NestLoop *node, EState *estate, int eflags) { NestLoopState *nlstate; + /* check for unsupported flags */ + Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK))); + NL1_printf("ExecInitNestLoop: %s\n", "initializing node"); @@ -309,9 +312,16 @@ ExecInitNestLoop(NestLoop *node, EState *estate) /* * initialize child nodes + * + * Tell the inner child that cheap rescans would be good. (This is + * unnecessary if we are doing nestloop with inner indexscan, because + * the rescan will always be with a fresh parameter --- but since + * nodeIndexscan doesn't actually care about REWIND, there's no point + * in dealing with that refinement.) */ - outerPlanState(nlstate) = ExecInitNode(outerPlan(node), estate); - innerPlanState(nlstate) = ExecInitNode(innerPlan(node), estate); + outerPlanState(nlstate) = ExecInitNode(outerPlan(node), estate, eflags); + innerPlanState(nlstate) = ExecInitNode(innerPlan(node), estate, + eflags | EXEC_FLAG_REWIND); #define NESTLOOP_NSLOTS 2 |