database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-30 11:03:19 +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

12
src/backend/executor/nodeHashjoin.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/nodeHashjoin.c,v 1.46 2002/12/30 15:21:20 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/executor/nodeHashjoin.c,v 1.47 2003/01/20 18:54:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -95,6 +95,15 @@ ExecHashJoin(HashJoinState *node)
node->js.ps.ps_TupFromTlist = false;
}
/*
* If we're doing an IN join, we want to return at most one row per
* outer tuple; so we can stop scanning the inner scan if we matched on
* the previous try.
*/
if (node->js.jointype == JOIN_IN &&
node->hj_MatchedOuter)
node->hj_NeedNewOuter = true;
/*
* Reset per-tuple memory context to free any expression evaluation
* storage allocated in the previous tuple cycle. Note this can't
@ -353,6 +362,7 @@ ExecInitHashJoin(HashJoin *node, EState *estate)
switch (node->join.jointype)
{
case JOIN_INNER:
case JOIN_IN:
break;
case JOIN_LEFT:
hjstate->hj_NullInnerTupleSlot =

16
src/backend/executor/nodeMergejoin.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/nodeMergejoin.c,v 1.55 2002/12/15 16:17:46 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/executor/nodeMergejoin.c,v 1.56 2003/01/20 18:54:45 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -381,6 +381,7 @@ ExecMergeJoin(MergeJoinState *node)
switch (node->js.jointype)
{
case JOIN_INNER:
case JOIN_IN:
doFillOuter = false;
doFillInner = false;
break;
@ -581,9 +582,15 @@ ExecMergeJoin(MergeJoinState *node)
* the econtext's tuple pointers were set up before
* checking the merge qual, so we needn't do it again.
*/
qualResult = (joinqual == NIL ||
ExecQual(joinqual, econtext, false));
MJ_DEBUG_QUAL(joinqual, qualResult);
if (node->js.jointype == JOIN_IN &&
node->mj_MatchedOuter)
qualResult = false;
else
{
qualResult = (joinqual == NIL ||
ExecQual(joinqual, econtext, false));
MJ_DEBUG_QUAL(joinqual, qualResult);
}
if (qualResult)
{
@ -1452,6 +1459,7 @@ ExecInitMergeJoin(MergeJoin *node, EState *estate)
switch (node->join.jointype)
{
case JOIN_INNER:
case JOIN_IN:
break;
case JOIN_LEFT:
mergestate->mj_NullInnerTupleSlot =

12
src/backend/executor/nodeNestloop.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/nodeNestloop.c,v 1.29 2002/12/15 16:17:46 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/executor/nodeNestloop.c,v 1.30 2003/01/20 18:54:46 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -101,6 +101,15 @@ ExecNestLoop(NestLoopState *node)
node->js.ps.ps_TupFromTlist = false;
}
/*
* If we're doing an IN join, we want to return at most one row per
* outer tuple; so we can stop scanning the inner scan if we matched on
* the previous try.
*/
if (node->js.jointype == JOIN_IN &&
node->nl_MatchedOuter)
node->nl_NeedNewOuter = true;
/*
* Reset per-tuple memory context to free any expression evaluation
* storage allocated in the previous tuple cycle. Note this can't
@ -312,6 +321,7 @@ ExecInitNestLoop(NestLoop *node, EState *estate)
switch (node->join.jointype)
{
case JOIN_INNER:
case JOIN_IN:
break;
case JOIN_LEFT:
nlstate->nl_NullInnerTupleSlot =