diff options
Diffstat (limited to 'src/backend/optimizer/util/keys.c')
| -rw-r--r-- | src/backend/optimizer/util/keys.c | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/src/backend/optimizer/util/keys.c b/src/backend/optimizer/util/keys.c index 0b89db898bc..12057bd2be0 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 1.11 1999/02/09 03:51:26 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/util/Attic/keys.c,v 1.12 1999/02/09 06:30:39 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -108,25 +108,35 @@ extract_subkey(JoinKey *jk, int which_subkey) /* * samekeys-- * Returns t iff two sets of path keys are equivalent. They are - * equivalent if the first subkey (var node) within each sublist of - * list 'keys1' is contained within the corresponding sublist of 'keys2'. + * equivalent if the first Var nodes match the second Var nodes. * * XXX It isn't necessary to check that each sublist exactly contain * the same elements because if the routine that built these * sublists together is correct, having one element in common * implies having all elements in common. + * Huh? bjm * */ bool samekeys(List *keys1, List *keys2) { List *key1, - *key2; + *key2, + *key1a, + *key2a; - for (key1 = keys1, key2 = keys2; key1 != NIL && key2 != NIL; + for (key1 = keys1, key2 = keys2; + key1 != NIL && key2 != NIL; key1 = lnext(key1), key2 = lnext(key2)) - if (!member(lfirst((List *)lfirst(key1)), lfirst(key2))) + { + for (key1a = lfirst(key1), key2a = lfirst(key2); + key1a != NIL && key2a != NIL; + key1a = lnext(key1a), key2a = lnext(key2a)) + if (!equal(lfirst(key1a), lfirst(key2a))) + return false; + if (key1a != NIL) return false; + } /* Now the result should be true if list keys2 has at least as many * entries as keys1, ie, we did not fall off the end of keys2 first. |