diff options
Diffstat (limited to 'src/backend/optimizer/util/keys.c')
| -rw-r--r-- | src/backend/optimizer/util/keys.c | 35 |
1 files changed, 27 insertions, 8 deletions
diff --git a/src/backend/optimizer/util/keys.c b/src/backend/optimizer/util/keys.c index bf9e91abb6b..1177f6bbb20 100644 --- a/src/backend/optimizer/util/keys.c +++ b/src/backend/optimizer/util/keys.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/util/Attic/keys.c,v 1.14 1999/02/10 21:02:41 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/util/Attic/keys.c,v 1.15 1999/02/11 04:08:42 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -106,7 +106,7 @@ extract_join_subkey(JoinKey *jk, int which_subkey) } /* - * samekeys-- + * pathkeys_match-- * Returns t iff two sets of path keys are equivalent. They are * equivalent if the first Var nodes match the second Var nodes. * @@ -118,7 +118,7 @@ extract_join_subkey(JoinKey *jk, int which_subkey) * */ bool -samekeys(List *keys1, List *keys2) +pathkeys_match(List *keys1, List *keys2, int *longer_key) { List *key1, *key2, @@ -133,9 +133,20 @@ samekeys(List *keys1, List *keys2) key1a != NIL && key2a != NIL; key1a = lnext(key1a), key2a = lnext(key2a)) if (!equal(lfirst(key1a), lfirst(key2a))) + { + *longer_key = 0; return false; - if (key1a != NIL) - return false; + } + if (key1a != NIL && key2a == NIL) + { + *longer_key = 1; + return true; + } + if (key1a == NIL && key2a != NIL) + { + *longer_key = 2; + return true; + } } /* Now the result should be true if list keys2 has at least as many @@ -143,10 +154,18 @@ samekeys(List *keys1, List *keys2) * If key1 is now NIL then we hit the end of keys1 before or at the * same time as the end of keys2. */ - if (key1 == NIL) + if (key1 != NIL && key2 == NIL) + { + *longer_key = 1; return true; - else - return false; + } + if (key1 == NIL && key2 != NIL) + { + *longer_key = 2; + return true; + } + *longer_key = 0; + return true; } /* |