diff options
Diffstat (limited to 'src/backend/optimizer/path/pathkeys.c')
| -rw-r--r-- | src/backend/optimizer/path/pathkeys.c | 57 |
1 files changed, 29 insertions, 28 deletions
diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c index 9fec73e2603..beb51a69966 100644 --- a/src/backend/optimizer/path/pathkeys.c +++ b/src/backend/optimizer/path/pathkeys.c @@ -11,7 +11,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/path/pathkeys.c,v 1.51 2003/07/25 00:01:07 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/path/pathkeys.c,v 1.52 2003/08/04 00:43:20 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -198,8 +198,8 @@ generate_implied_equalities(Query *root) /* * Collect info about relids mentioned in each item. For this * routine we only really care whether there are any at all in - * each item, but process_implied_equality() needs the exact - * sets, so we may as well pull them here. + * each item, but process_implied_equality() needs the exact sets, + * so we may as well pull them here. */ relids = (Relids *) palloc(nitems * sizeof(Relids)); have_consts = false; @@ -233,8 +233,8 @@ generate_implied_equalities(Query *root) /* * If it's "const = const" then just ignore it altogether. - * There is no place in the restrictinfo structure to store - * it. (If the two consts are in fact unequal, then + * There is no place in the restrictinfo structure to + * store it. (If the two consts are in fact unequal, then * propagating the comparison to Vars will cause us to * produce zero rows out, as expected.) */ @@ -242,12 +242,12 @@ generate_implied_equalities(Query *root) { /* * Tell process_implied_equality to delete the clause, - * not add it, if it's "var = var" and we have constants - * present in the list. + * not add it, if it's "var = var" and we have + * constants present in the list. */ - bool delete_it = (have_consts && - i1_is_variable && - i2_is_variable); + bool delete_it = (have_consts && + i1_is_variable && + i2_is_variable); process_implied_equality(root, item1->key, item2->key, @@ -751,20 +751,21 @@ build_subquery_pathkeys(Query *root, RelOptInfo *rel, Query *subquery) * element might match none, one, or more of the output columns * that are visible to the outer query. This means we may have * multiple possible representations of the sub_pathkey in the - * context of the outer query. Ideally we would generate them all - * and put them all into a pathkey list of the outer query, thereby - * propagating equality knowledge up to the outer query. Right now - * we cannot do so, because the outer query's canonical pathkey - * sets are already frozen when this is called. Instead we prefer - * the one that has the highest "score" (number of canonical pathkey - * peers, plus one if it matches the outer query_pathkeys). - * This is the most likely to be useful in the outer query. + * context of the outer query. Ideally we would generate them all + * and put them all into a pathkey list of the outer query, + * thereby propagating equality knowledge up to the outer query. + * Right now we cannot do so, because the outer query's canonical + * pathkey sets are already frozen when this is called. Instead + * we prefer the one that has the highest "score" (number of + * canonical pathkey peers, plus one if it matches the outer + * query_pathkeys). This is the most likely to be useful in the + * outer query. */ foreach(j, sub_pathkey) { PathKeyItem *sub_item = (PathKeyItem *) lfirst(j); - Node *sub_key = sub_item->key; - List *k; + Node *sub_key = sub_item->key; + List *k; foreach(k, subquery->targetList) { @@ -774,9 +775,9 @@ build_subquery_pathkeys(Query *root, RelOptInfo *rel, Query *subquery) equal(tle->expr, sub_key)) { /* Found a representation for this sub_key */ - Var *outer_var; + Var *outer_var; PathKeyItem *outer_item; - int score; + int score; outer_var = makeVar(rel->relid, tle->resdom->resno, @@ -802,8 +803,8 @@ build_subquery_pathkeys(Query *root, RelOptInfo *rel, Query *subquery) } /* - * If we couldn't find a representation of this sub_pathkey, - * we're done (we can't use the ones to its right, either). + * If we couldn't find a representation of this sub_pathkey, we're + * done (we can't use the ones to its right, either). */ if (!best_item) break; @@ -812,8 +813,8 @@ build_subquery_pathkeys(Query *root, RelOptInfo *rel, Query *subquery) cpathkey = make_canonical_pathkey(root, best_item); /* - * Eliminate redundant ordering info; could happen if outer - * query equijoins subquery keys... + * Eliminate redundant ordering info; could happen if outer query + * equijoins subquery keys... */ if (!ptrMember(cpathkey, retval)) { @@ -920,7 +921,7 @@ make_pathkeys_for_sortclauses(List *sortclauses, * many times when dealing with a many-relation query. * * We have to be careful that the cached values are palloc'd in the same - * context the RestrictInfo node itself is in. This is not currently a + * context the RestrictInfo node itself is in. This is not currently a * problem for normal planning, but it is an issue for GEQO planning. */ void @@ -1090,7 +1091,7 @@ make_pathkeys_for_mergeclauses(Query *root, else { elog(ERROR, "could not identify which side of mergeclause to use"); - pathkey = NIL; /* keep compiler quiet */ + pathkey = NIL; /* keep compiler quiet */ } /* |