diff options
Diffstat (limited to 'src/backend/optimizer/util/ordering.c')
| -rw-r--r-- | src/backend/optimizer/util/ordering.c | 78 |
1 files changed, 63 insertions, 15 deletions
diff --git a/src/backend/optimizer/util/ordering.c b/src/backend/optimizer/util/ordering.c index 59da32deb46..8e5fb15baf2 100644 --- a/src/backend/optimizer/util/ordering.c +++ b/src/backend/optimizer/util/ordering.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/util/Attic/ordering.c,v 1.11 1999/02/06 17:29:27 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/util/Attic/ordering.c,v 1.12 1999/02/11 14:58:58 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -18,7 +18,7 @@ #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, int *more_sort); /* * equal-path-ordering-- @@ -26,14 +26,27 @@ static bool equal_sortops_order(Oid *ordering1, Oid *ordering2); * */ bool -equal_path_ordering(PathOrder *path_ordering1, - PathOrder *path_ordering2) +pathorder_match(PathOrder *path_ordering1, + PathOrder *path_ordering2, + int *more_sort) { + + *more_sort = 0; + if (path_ordering1 == path_ordering2) return true; + + if (!path_ordering2) + { + *more_sort = 1; + return true; + } - if (!path_ordering1 || !path_ordering2) - return false; + if (!path_ordering1) + { + *more_sort = 2; + return true; + } if (path_ordering1->ordtype == MERGE_ORDER && path_ordering2->ordtype == MERGE_ORDER) @@ -43,19 +56,28 @@ equal_path_ordering(PathOrder *path_ordering1, else if (path_ordering1->ordtype == SORTOP_ORDER && path_ordering2->ordtype == SORTOP_ORDER) { - return (equal_sortops_order(path_ordering1->ord.sortop, - path_ordering2->ord.sortop)); + return equal_sortops_order(path_ordering1->ord.sortop, + path_ordering2->ord.sortop, + more_sort); } 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])); + if (!path_ordering2->ord.sortop) + { + *more_sort = 1; + return true; + } + return 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->ord.sortop) + { + *more_sort = 2; + return true; + } + return path_ordering1->ord.sortop[0] == path_ordering2->ord.merge->left_operator; } } @@ -105,13 +127,27 @@ equal_merge_ordering(MergeOrder *merge_ordering1, * Returns true iff the sort operators are in the same order. */ static bool -equal_sortops_order(Oid *ordering1, Oid *ordering2) +equal_sortops_order(Oid *ordering1, Oid *ordering2, int *more_sort) { int i = 0; - if (ordering1 == NULL || ordering2 == NULL) - return ordering1 == ordering2; + *more_sort = 0; + + if (ordering1 == ordering2) + return true; + if (!ordering2) + { + *more_sort = 1; + return true; + } + + if (!ordering1) + { + *more_sort = 2; + return true; + } + while (ordering1[i] != 0 && ordering2[i] != 0) { if (ordering1[i] != ordering2[i]) @@ -119,5 +155,17 @@ equal_sortops_order(Oid *ordering1, Oid *ordering2) i++; } + if (ordering1[i] != 0 && ordering2[i] == 0) + { + *more_sort = 1; + return true; + } + + if (ordering1[i] == 0 && ordering2[i] != 0) + { + *more_sort = 2; + return true; + } + return ordering1[i] == 0 && ordering2[i] == 0; } |