diff options
Diffstat (limited to 'src/include/nodes/nodes.h')
| -rw-r--r-- | src/include/nodes/nodes.h | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h index ddd9934cf1e..4161c08ec54 100644 --- a/src/include/nodes/nodes.h +++ b/src/include/nodes/nodes.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.214 2008/10/21 20:42:53 tgl Exp $ + * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.215 2008/11/22 22:47:06 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -542,15 +542,23 @@ typedef enum JoinType /* * OUTER joins are those for which pushed-down quals must behave differently - * from the join's own quals. This is in fact everything except INNER joins. - * However, this macro must also exclude the JOIN_UNIQUE symbols since those - * are temporary proxies for what will eventually be an INNER join. + * from the join's own quals. This is in fact everything except INNER and + * SEMI joins. However, this macro must also exclude the JOIN_UNIQUE symbols + * since those are temporary proxies for what will eventually be an INNER + * join. * - * Note: in some places it is preferable to treat JOIN_SEMI as not being - * an outer join, since it doesn't produce null-extended rows. Be aware - * of that distinction when deciding whether to use this macro. + * Note: semijoins are a hybrid case, but we choose to treat them as not + * being outer joins. This is okay principally because the SQL syntax makes + * it impossible to have a pushed-down qual that refers to the inner relation + * of a semijoin; so there is no strong need to distinguish join quals from + * pushed-down quals. This is convenient because for almost all purposes, + * quals attached to a semijoin can be treated the same as innerjoin quals. */ #define IS_OUTER_JOIN(jointype) \ - ((jointype) > JOIN_INNER && (jointype) < JOIN_UNIQUE_OUTER) + (((1 << (jointype)) & \ + ((1 << JOIN_LEFT) | \ + (1 << JOIN_FULL) | \ + (1 << JOIN_RIGHT) | \ + (1 << JOIN_ANTI))) != 0) #endif /* NODES_H */ |