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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2005-07-02 23:00:42 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2005-07-02 23:00:42 +0000 |
| commit | cc5e80b8d1c4bf86aa99b54c938e9048e10bf93a (patch) | |
| tree | 6288e2b3bf66c8b1d30ee6db9b7846251d5ad95a /src/include/optimizer/restrictinfo.h | |
| parent | ea1e2b948d2dcbd40fb9053e74ae2da27cfd425e (diff) | |
| download | postgresql-cc5e80b8d1c4bf86aa99b54c938e9048e10bf93a.tar.gz postgresql-cc5e80b8d1c4bf86aa99b54c938e9048e10bf93a.zip | |
Teach planner about some cases where a restriction clause can be
propagated inside an outer join. In particular, given
LEFT JOIN ON (A = B) WHERE A = constant, we cannot conclude that
B = constant at the top level (B might be null instead), but we
can nonetheless put a restriction B = constant into the quals for
B's relation, since no inner-side rows not meeting that condition
can contribute to the final result. Similarly, given
FULL JOIN USING (J) WHERE J = constant, we can't directly conclude
that either input J variable = constant, but it's OK to push such
quals into each input rel. Per recent gripe from Kim Bisgaard.
Along the way, remove 'valid_everywhere' flag from RestrictInfo,
as on closer analysis it was not being used for anything, and was
defined backwards anyway.
Diffstat (limited to 'src/include/optimizer/restrictinfo.h')
| -rw-r--r-- | src/include/optimizer/restrictinfo.h | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/src/include/optimizer/restrictinfo.h b/src/include/optimizer/restrictinfo.h index 20f51c58204..5a9c2f27224 100644 --- a/src/include/optimizer/restrictinfo.h +++ b/src/include/optimizer/restrictinfo.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/optimizer/restrictinfo.h,v 1.31 2005/06/09 04:19:00 tgl Exp $ + * $PostgreSQL: pgsql/src/include/optimizer/restrictinfo.h,v 1.32 2005/07/02 23:00:42 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -19,11 +19,9 @@ extern RestrictInfo *make_restrictinfo(Expr *clause, bool is_pushed_down, - bool valid_everywhere, Relids required_relids); extern List *make_restrictinfo_from_bitmapqual(Path *bitmapqual, - bool is_pushed_down, - bool valid_everywhere); + bool is_pushed_down); extern bool restriction_is_or_clause(RestrictInfo *restrictinfo); extern List *get_actual_clauses(List *restrictinfo_list); extern void get_actual_join_clauses(List *restrictinfo_list, |