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Optimizer fix for samekeys.

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This commit is contained in:
Bruce Momjian
1999-02-09 06:30:45 +00:00
parent fe35ffe7e0
commit 78511d8fe9
3 changed files with 5732 additions and 5520 deletions
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22
src/backend/optimizer/util/keys.c
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@@ -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.