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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.
37 lines
1.3 KiB
C
37 lines
1.3 KiB
C
/*-------------------------------------------------------------------------
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*
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* restrictinfo.h
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* prototypes for restrictinfo.c.
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*
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*
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* Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* $PostgreSQL: pgsql/src/include/optimizer/restrictinfo.h,v 1.32 2005/07/02 23:00:42 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef RESTRICTINFO_H
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#define RESTRICTINFO_H
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#include "nodes/relation.h"
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extern RestrictInfo *make_restrictinfo(Expr *clause,
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bool is_pushed_down,
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Relids required_relids);
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extern List *make_restrictinfo_from_bitmapqual(Path *bitmapqual,
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bool is_pushed_down);
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extern bool restriction_is_or_clause(RestrictInfo *restrictinfo);
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extern List *get_actual_clauses(List *restrictinfo_list);
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extern void get_actual_join_clauses(List *restrictinfo_list,
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List **joinquals, List **otherquals);
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extern List *remove_redundant_join_clauses(PlannerInfo *root,
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List *restrictinfo_list,
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bool isouterjoin);
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extern List *select_nonredundant_join_clauses(PlannerInfo *root,
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List *restrictinfo_list,
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List *reference_list,
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bool isouterjoin);
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#endif /* RESTRICTINFO_H */
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