database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-06 07:49:08 +03:00
Code Activity

aggregate(DISTINCT ...) works, per SQL spec.

Browse Source 
Note this forces initdb because of change of Aggref node in stored rules.
This commit is contained in:
Tom Lane
1999-12-13 01:27:21 +00:00
parent efb36d2be8
commit a8ae19ec3d
16 changed files with 771 additions and 269 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
src/backend/optimizer/util/clauses.c
View File

@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.56 1999/12/09 05:58:53 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.57 1999/12/13 01:26:55 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@@ -45,6 +45,7 @@ typedef struct {
List *targetList;
} check_subplans_for_ungrouped_vars_context;
static bool contain_agg_clause_walker(Node *node, void *context);
static bool pull_agg_clause_walker(Node *node, List **listptr);
static bool check_subplans_for_ungrouped_vars_walker(Node *node,
check_subplans_for_ungrouped_vars_context *context);
@@ -393,12 +394,36 @@ pull_constant_clauses(List *quals, List **constantQual)
return restqual;
}
/*
* contain_agg_clause
* Recursively search for Aggref nodes within a clause.
*
* Returns true if any aggregate found.
*/
bool
contain_agg_clause(Node *clause)
{
return contain_agg_clause_walker(clause, NULL);
}
static bool
contain_agg_clause_walker(Node *node, void *context)
{
if (node == NULL)
return false;
if (IsA(node, Aggref))
return true; /* abort the tree traversal and return true */
return expression_tree_walker(node, contain_agg_clause_walker, context);
}
/*
* pull_agg_clause
* Recursively pulls all Aggref nodes from an expression tree.
*
* Returns list of Aggref nodes found. Note the nodes themselves are not
* copied, only referenced.
*
* Note: this also checks for nested aggregates, which are an error.
*/
List *
pull_agg_clause(Node *clause)
@@ -417,9 +442,16 @@ pull_agg_clause_walker(Node *node, List **listptr)
if (IsA(node, Aggref))
{
*listptr = lappend(*listptr, node);
/* continue, to iterate over agg's arg as well (do nested aggregates
* actually work?)
/*
* Complain if the aggregate's argument contains any aggregates;
* nested agg functions are semantically nonsensical.
*/
if (contain_agg_clause(((Aggref *) node)->target))
elog(ERROR, "Aggregate function calls may not be nested");
/*
* Having checked that, we need not recurse into the argument.
*/
return false;
}
return expression_tree_walker(node, pull_agg_clause_walker,
(void *) listptr);