diff options
Diffstat (limited to 'src/backend/optimizer/util/clauses.c')
| -rw-r--r-- | src/backend/optimizer/util/clauses.c | 36 |
1 files changed, 35 insertions, 1 deletions
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index d00867d6480..b3d50433564 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 1.91 2001/11/05 17:46:26 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.92 2001/12/10 22:54:12 tgl Exp $ * * HISTORY * AUTHOR DATE MAJOR EVENT @@ -47,6 +47,7 @@ typedef struct static bool contain_agg_clause_walker(Node *node, void *context); static bool pull_agg_clause_walker(Node *node, List **listptr); +static bool contain_iter_clause_walker(Node *node, void *context); static bool contain_subplans_walker(Node *node, void *context); static bool pull_subplans_walker(Node *node, List **listptr); static bool check_subplans_for_ungrouped_vars_walker(Node *node, @@ -451,6 +452,39 @@ pull_agg_clause_walker(Node *node, List **listptr) /***************************************************************************** + * Iter clause manipulation + *****************************************************************************/ + +/* + * contain_iter_clause + * Recursively search for Iter nodes within a clause. + * + * Returns true if any Iter found. + * + * XXX Iter is a crock. It'd be better to look directly at each function + * or operator to see if it can return a set. However, that would require + * a lot of extra cycles as things presently stand. The return-type info + * for function and operator nodes should be extended to include whether + * the return is a set. + */ +bool +contain_iter_clause(Node *clause) +{ + return contain_iter_clause_walker(clause, NULL); +} + +static bool +contain_iter_clause_walker(Node *node, void *context) +{ + if (node == NULL) + return false; + if (IsA(node, Iter)) + return true; /* abort the tree traversal and return + * true */ + return expression_tree_walker(node, contain_iter_clause_walker, context); +} + +/***************************************************************************** * Subplan clause manipulation *****************************************************************************/ |