diff options
Diffstat (limited to 'src/backend/optimizer/util/clauses.c')
| -rw-r--r-- | src/backend/optimizer/util/clauses.c | 44 |
1 files changed, 25 insertions, 19 deletions
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index edf77faff02..ee037974769 100644 --- a/src/backend/optimizer/util/clauses.c +++ b/src/backend/optimizer/util/clauses.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.108 2002/09/04 20:31:22 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.109 2002/09/11 14:48:54 tgl Exp $ * * HISTORY * AUTHOR DATE MAJOR EVENT @@ -1788,7 +1788,7 @@ simplify_op_or_func(Expr *expr, List *args) * { * adjust context for subquery; * result = query_tree_walker((Query *) node, my_walker, context, - * true); // to visit subquery RTEs too + * 0); // to visit rtable items too * restore context if needed; * return result; * } @@ -1994,16 +1994,17 @@ expression_tree_walker(Node *node, * walker intends to descend into subqueries. It is also useful for * descending into subqueries within a walker. * - * If visitQueryRTEs is true, the walker will also be called on sub-Query - * nodes present in subquery rangetable entries of the given Query. This - * is optional since some callers handle those sub-queries separately, - * or don't really want to see subqueries anyway. + * Some callers want to suppress visitation of certain items in the sub-Query, + * typically because they need to process them specially, or don't actually + * want to recurse into subqueries. This is supported by the flags argument, + * which is the bitwise OR of flag values to suppress visitation of + * indicated items. (More flag bits may be added as needed.) */ bool query_tree_walker(Query *query, bool (*walker) (), void *context, - bool visitQueryRTEs) + int flags) { List *rt; @@ -2028,13 +2029,14 @@ query_tree_walker(Query *query, /* nothing to do */ break; case RTE_SUBQUERY: - if (visitQueryRTEs) + if (! (flags & QTW_IGNORE_SUBQUERIES)) if (walker(rte->subquery, context)) return true; break; case RTE_JOIN: - if (walker(rte->joinaliasvars, context)) - return true; + if (! (flags & QTW_IGNORE_JOINALIASES)) + if (walker(rte->joinaliasvars, context)) + return true; break; case RTE_FUNCTION: if (walker(rte->funcexpr, context)) @@ -2388,16 +2390,17 @@ expression_tree_mutator(Node *node, * if you don't want to change the original. All substructure is safely * copied, however. * - * If visitQueryRTEs is true, the mutator will also be called on sub-Query - * nodes present in subquery rangetable entries of the given Query. This - * is optional since some callers handle those sub-queries separately, - * or don't really want to see subqueries anyway. + * Some callers want to suppress mutating of certain items in the sub-Query, + * typically because they need to process them specially, or don't actually + * want to recurse into subqueries. This is supported by the flags argument, + * which is the bitwise OR of flag values to suppress mutating of + * indicated items. (More flag bits may be added as needed.) */ void query_tree_mutator(Query *query, Node *(*mutator) (), void *context, - bool visitQueryRTEs) + int flags) { List *newrt = NIL; List *rt; @@ -2420,7 +2423,7 @@ query_tree_mutator(Query *query, /* nothing to do, don't bother to make a copy */ break; case RTE_SUBQUERY: - if (visitQueryRTEs) + if (! (flags & QTW_IGNORE_SUBQUERIES)) { FLATCOPY(newrte, rte, RangeTblEntry); CHECKFLATCOPY(newrte->subquery, rte->subquery, Query); @@ -2429,9 +2432,12 @@ query_tree_mutator(Query *query, } break; case RTE_JOIN: - FLATCOPY(newrte, rte, RangeTblEntry); - MUTATE(newrte->joinaliasvars, rte->joinaliasvars, List *); - rte = newrte; + if (! (flags & QTW_IGNORE_JOINALIASES)) + { + FLATCOPY(newrte, rte, RangeTblEntry); + MUTATE(newrte->joinaliasvars, rte->joinaliasvars, List *); + rte = newrte; + } break; case RTE_FUNCTION: FLATCOPY(newrte, rte, RangeTblEntry); |