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

IN clauses appearing at top level of WHERE can now be handled as joins.

Browse Source 
There are two implementation techniques: the executor understands a new
JOIN_IN jointype, which emits at most one matching row per left-hand row,
or the result of the IN's sub-select can be fed through a DISTINCT filter
and then joined as an ordinary relation.
Along the way, some minor code cleanup in the optimizer; notably, break
out most of the jointree-rearrangement preprocessing in planner.c and
put it in a new file prep/prepjointree.c.
This commit is contained in:
Tom Lane
2003-01-20 18:55:07 +00:00
parent be2b660ecd
commit bdfbfde1b1
47 changed files with 2075 additions and 875 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
src/backend/optimizer/util/clauses.c
View File

@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.124 2003/01/17 03:25:03 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.125 2003/01/20 18:54:54 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@@ -2200,6 +2200,15 @@ expression_tree_walker(Node *node,
return true;
}
break;
case T_InClauseInfo:
{
InClauseInfo *ininfo = (InClauseInfo *) node;
if (expression_tree_walker((Node *) ininfo->sub_targetlist,
walker, context))
return true;
}
break;
default:
elog(ERROR, "expression_tree_walker: Unexpected node type %d",
nodeTag(node));
@@ -2241,6 +2250,8 @@ query_tree_walker(Query *query,
return true;
if (walker(query->havingQual, context))
return true;
if (walker(query->in_info_list, context))
return true;
foreach(rt, query->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);
@@ -2610,6 +2621,16 @@ expression_tree_mutator(Node *node,
return (Node *) newnode;
}
break;
case T_InClauseInfo:
{
InClauseInfo *ininfo = (InClauseInfo *) node;
InClauseInfo *newnode;
FLATCOPY(newnode, ininfo, InClauseInfo);
MUTATE(newnode->sub_targetlist, ininfo->sub_targetlist, List *);
return (Node *) newnode;
}
break;
default:
elog(ERROR, "expression_tree_mutator: Unexpected node type %d",
nodeTag(node));
@@ -2662,6 +2683,7 @@ query_tree_mutator(Query *query,
MUTATE(query->jointree, query->jointree, FromExpr *);
MUTATE(query->setOperations, query->setOperations, Node *);
MUTATE(query->havingQual, query->havingQual, Node *);
MUTATE(query->in_info_list, query->in_info_list, List *);
foreach(rt, query->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(rt);