diff options
Diffstat (limited to 'src/backend/optimizer/util/ordering.c')
| -rw-r--r-- | src/backend/optimizer/util/ordering.c | 154 |
1 files changed, 81 insertions, 73 deletions
diff --git a/src/backend/optimizer/util/ordering.c b/src/backend/optimizer/util/ordering.c index 40699e81e0b..504d48bdce5 100644 --- a/src/backend/optimizer/util/ordering.c +++ b/src/backend/optimizer/util/ordering.c @@ -1,13 +1,13 @@ /*------------------------------------------------------------------------- * * ordering.c-- - * Routines to manipulate and compare merge and path orderings + * Routines to manipulate and compare merge and path orderings * * Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/util/Attic/ordering.c,v 1.3 1997/08/19 21:32:06 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/util/Attic/ordering.c,v 1.4 1997/09/07 04:44:30 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -18,81 +18,88 @@ #include "optimizer/internal.h" #include "optimizer/ordering.h" -static bool equal_sortops_order(Oid *ordering1, Oid *ordering2); +static bool equal_sortops_order(Oid * ordering1, Oid * ordering2); -/* +/* * equal-path-path-ordering-- - * Returns t iff two path orderings are equal. - * + * Returns t iff two path orderings are equal. + * */ bool -equal_path_path_ordering(PathOrder *path_ordering1, - PathOrder *path_ordering2) +equal_path_path_ordering(PathOrder * path_ordering1, + PathOrder * path_ordering2) { - if (path_ordering1 == path_ordering2) - return true; - - if (!path_ordering1 || !path_ordering2) - return false; - - if (path_ordering1->ordtype == MERGE_ORDER && - path_ordering2->ordtype == MERGE_ORDER) { - - return equal(path_ordering1->ord.merge, path_ordering2->ord.merge); - - } else if (path_ordering1->ordtype == SORTOP_ORDER && - path_ordering2->ordtype == SORTOP_ORDER) { - - return - (equal_sortops_order(path_ordering1->ord.sortop, - path_ordering2->ord.sortop)); - } else if (path_ordering1->ordtype == MERGE_ORDER && - path_ordering2->ordtype == SORTOP_ORDER) { - - return (path_ordering2->ord.sortop && - (path_ordering1->ord.merge->left_operator == - path_ordering2->ord.sortop[0])); - } else { - - return (path_ordering1->ord.sortop && - (path_ordering1->ord.sortop[0] == - path_ordering2->ord.merge->left_operator)); - } + if (path_ordering1 == path_ordering2) + return true; + + if (!path_ordering1 || !path_ordering2) + return false; + + if (path_ordering1->ordtype == MERGE_ORDER && + path_ordering2->ordtype == MERGE_ORDER) + { + + return equal(path_ordering1->ord.merge, path_ordering2->ord.merge); + + } + else if (path_ordering1->ordtype == SORTOP_ORDER && + path_ordering2->ordtype == SORTOP_ORDER) + { + + return + (equal_sortops_order(path_ordering1->ord.sortop, + path_ordering2->ord.sortop)); + } + else if (path_ordering1->ordtype == MERGE_ORDER && + path_ordering2->ordtype == SORTOP_ORDER) + { + + return (path_ordering2->ord.sortop && + (path_ordering1->ord.merge->left_operator == + path_ordering2->ord.sortop[0])); + } + else + { + + return (path_ordering1->ord.sortop && + (path_ordering1->ord.sortop[0] == + path_ordering2->ord.merge->left_operator)); + } } -/* +/* * equal-path-merge-ordering-- - * Returns t iff a path ordering is usable for ordering a merge join. + * Returns t iff a path ordering is usable for ordering a merge join. * * XXX Presently, this means that the first sortop of the path matches - * either of the merge sortops. Is there a "right" and "wrong" - * sortop to match? - * + * either of the merge sortops. Is there a "right" and "wrong" + * sortop to match? + * */ bool -equal_path_merge_ordering(Oid *path_ordering, - MergeOrder *merge_ordering) +equal_path_merge_ordering(Oid * path_ordering, + MergeOrder * merge_ordering) { - if (path_ordering == NULL || merge_ordering == NULL) - return(false); - - if (path_ordering[0] == merge_ordering->left_operator || - path_ordering[0] == merge_ordering->right_operator) - return(true); - else - return(false); + if (path_ordering == NULL || merge_ordering == NULL) + return (false); + + if (path_ordering[0] == merge_ordering->left_operator || + path_ordering[0] == merge_ordering->right_operator) + return (true); + else + return (false); } -/* +/* * equal-merge-merge-ordering-- - * Returns t iff two merge orderings are equal. - * + * Returns t iff two merge orderings are equal. + * */ bool -equal_merge_merge_ordering(MergeOrder *merge_ordering1, - MergeOrder *merge_ordering2) +equal_merge_merge_ordering(MergeOrder * merge_ordering1, + MergeOrder * merge_ordering2) { - return (equal(merge_ordering1, merge_ordering2)); + return (equal(merge_ordering1, merge_ordering2)); } /***************************************************************************** @@ -101,21 +108,22 @@ equal_merge_merge_ordering(MergeOrder *merge_ordering1, /* * equal_sort_ops_order - - * Returns true iff the sort operators are in the same order. + * Returns true iff the sort operators are in the same order. */ -static bool -equal_sortops_order(Oid *ordering1, Oid *ordering2) +static bool +equal_sortops_order(Oid * ordering1, Oid * ordering2) { - int i = 0; - - if (ordering1 == NULL || ordering2 == NULL) - return (ordering1==ordering2); - - while (ordering1[i]!=0 && ordering2[i]!=0) { - if (ordering1[i] != ordering2[i]) - break; - i++; - } - - return (ordering1[i]==0 && ordering2[i]==0); + int i = 0; + + if (ordering1 == NULL || ordering2 == NULL) + return (ordering1 == ordering2); + + while (ordering1[i] != 0 && ordering2[i] != 0) + { + if (ordering1[i] != ordering2[i]) + break; + i++; + } + + return (ordering1[i] == 0 && ordering2[i] == 0); } |