diff options
Diffstat (limited to 'src/include/nodes/primnodes.h')
| -rw-r--r-- | src/include/nodes/primnodes.h | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h index 285a0008fdc..d9ea05994dd 100644 --- a/src/include/nodes/primnodes.h +++ b/src/include/nodes/primnodes.h @@ -10,7 +10,7 @@ * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: primnodes.h,v 1.75 2002/12/14 00:17:59 tgl Exp $ + * $Id: primnodes.h,v 1.76 2003/01/09 20:50:53 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -374,7 +374,7 @@ typedef struct BoolExpr * MULTIEXPR and EXPR require the subselect to deliver only one row. * ALL, ANY, and MULTIEXPR require the combining operators to deliver boolean * results. These are reduced to one result per row using OR or AND semantics - * depending on the "useor" flag. ALL and ANY combine the per-row results + * depending on the "useOr" flag. ALL and ANY combine the per-row results * using AND and OR semantics respectively. * * SubLink is classed as an Expr node, but it is not actually executable; @@ -395,7 +395,11 @@ typedef struct BoolExpr * rewriter. * * In EXISTS and EXPR SubLinks, both lefthand and oper are unused and are - * always NIL. useor is not significant either for these sublink types. + * always NIL. useOr is not significant either for these sublink types. + * + * The operIsEquals field is TRUE when the combining operator was written as + * "=" --- if the subLinkType is ANY_SUBLINK, this means the operation is + * equivalent to "IN". This case allows special optimizations to be used. * ---------------- */ typedef enum SubLinkType @@ -408,7 +412,8 @@ typedef struct SubLink { Expr xpr; SubLinkType subLinkType; /* EXISTS, ALL, ANY, MULTIEXPR, EXPR */ - bool useor; /* TRUE to combine column results with + bool operIsEquals; /* TRUE if combining operator is "=" */ + bool useOr; /* TRUE to combine column results with * "OR" not "AND" */ List *lefthand; /* list of outer-query expressions on the * left */ @@ -446,7 +451,7 @@ typedef struct SubPlan Expr xpr; /* Fields copied from original SubLink: */ SubLinkType subLinkType; /* EXISTS, ALL, ANY, MULTIEXPR, EXPR */ - bool useor; /* TRUE to combine column results with + bool useOr; /* TRUE to combine column results with * "OR" not "AND" */ List *oper; /* list of executable expressions for * combining operators (with arguments) */ |