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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2009-09-12 22:12:09 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2009-09-12 22:12:09 +0000 |
| commit | 9bb342811bf6a93a574a648c5848feedbaaef8f2 (patch) | |
| tree | ecc60f3017cc58695c4c96ebf6d11669e3de6900 /src/include/executor | |
| parent | 5f1b32ddf826550d65dd6e84b965b6a98589ad19 (diff) | |
| download | postgresql-9bb342811bf6a93a574a648c5848feedbaaef8f2.tar.gz postgresql-9bb342811bf6a93a574a648c5848feedbaaef8f2.zip | |
Rewrite the planner's handling of materialized plan types so that there is
an explicit model of rescan costs being different from first-time costs.
The costing of Material nodes in particular now has some visible relationship
to the actual runtime behavior, where before it was essentially fantasy.
This also fixes up a couple of places where different materialized plan types
were treated differently for no very good reason (probably just oversights).
A couple of the regression tests are affected, because the planner now chooses
to put the other relation on the inside of a nestloop-with-materialize.
So far as I can see both changes are sane, and the planner is now more
consistently following the expectation that it should prefer to materialize
the smaller of two relations.
Per a recent discussion with Robert Haas.
Diffstat (limited to 'src/include/executor')
| -rw-r--r-- | src/include/executor/executor.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/include/executor/executor.h b/src/include/executor/executor.h index 2ad1e26b2a1..c395eadc370 100644 --- a/src/include/executor/executor.h +++ b/src/include/executor/executor.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/executor/executor.h,v 1.158 2009/07/29 20:56:20 tgl Exp $ + * $PostgreSQL: pgsql/src/include/executor/executor.h,v 1.159 2009/09/12 22:12:04 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -83,6 +83,7 @@ extern void ExecMarkPos(PlanState *node); extern void ExecRestrPos(PlanState *node); extern bool ExecSupportsMarkRestore(NodeTag plantype); extern bool ExecSupportsBackwardScan(Plan *node); +extern bool ExecMaterializesOutput(NodeTag plantype); /* * prototypes from functions in execCurrent.c |