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

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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
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35
src/backend/optimizer/util/joininfo.c
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@@ -8,37 +8,29 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/joininfo.c,v 1.31 2002/06/20 20:29:31 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/joininfo.c,v 1.32 2003/01/20 18:54:56 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "optimizer/joininfo.h"
static JoinInfo *joininfo_member(List *join_relids, List *joininfo_list);
/*
* joininfo_member
* Determines whether a node has already been created for a join
* between a set of join relations and the relation described by
* 'joininfo_list'.
*
* 'join_relids' is a list of relids corresponding to the join relation
* 'joininfo_list' is the list of joininfo nodes against which this is
* checked
*
* Returns the corresponding node in 'joininfo_list' if such a node
* exists.
* find_joininfo_node
* Find the joininfo node within a relation entry corresponding
* to a join between 'this_rel' and the relations in 'join_relids'.
* If there is no such node, return NULL.
*
* Returns a joininfo node, or NULL.
*/
static JoinInfo *
joininfo_member(List *join_relids, List *joininfo_list)
JoinInfo *
find_joininfo_node(RelOptInfo *this_rel, Relids join_relids)
{
List *i;
foreach(i, joininfo_list)
foreach(i, this_rel->joininfo)
{
JoinInfo *joininfo = (JoinInfo *) lfirst(i);
@@ -48,22 +40,19 @@ joininfo_member(List *join_relids, List *joininfo_list)
return NULL;
}
/*
* find_joininfo_node
* make_joininfo_node
* Find the joininfo node within a relation entry corresponding
* to a join between 'this_rel' and the relations in 'join_relids'.
* A new node is created and added to the relation entry's joininfo
* field if the desired one can't be found.
*
* Returns a joininfo node.
*
*/
JoinInfo *
find_joininfo_node(RelOptInfo *this_rel, Relids join_relids)
make_joininfo_node(RelOptInfo *this_rel, Relids join_relids)
{
JoinInfo *joininfo = joininfo_member(join_relids,
this_rel->joininfo);
JoinInfo *joininfo = find_joininfo_node(this_rel, join_relids);
if (joininfo == NULL)
{