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Create a new 'MultiExecProcNode' call API for plan nodes that don't

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return just a single tuple at a time.  Currently the only such node
type is Hash, but I expect we will soon have indexscans that can return
tuple bitmaps.  A side benefit is that EXPLAIN ANALYZE now shows the
correct tuple count for a Hash node.
This commit is contained in:
Tom Lane
2005-04-16 20:07:35 +00:00
parent 85eee28cec
commit d8b1bf4791
9 changed files with 121 additions and 39 deletions
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42
src/backend/executor/nodeHash.c
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@ -8,13 +8,13 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/executor/nodeHash.c,v 1.92 2005/03/31 02:02:52 neilc Exp $
* $PostgreSQL: pgsql/src/backend/executor/nodeHash.c,v 1.93 2005/04/16 20:07:35 tgl Exp $
*
*-------------------------------------------------------------------------
*/
/*
* INTERFACE ROUTINES
* ExecHash - generate an in-memory hash table of the relation
* MultiExecHash - generate an in-memory hash table of the relation
* ExecInitHash - initialize node and subnodes
* ExecEndHash - shutdown node and subnodes
*/
@ -22,6 +22,7 @@
#include "executor/execdebug.h"
#include "executor/hashjoin.h"
#include "executor/instrument.h"
#include "executor/nodeHash.h"
#include "executor/nodeHashjoin.h"
#include "miscadmin.h"
@ -36,12 +37,25 @@ static void ExecHashIncreaseNumBatches(HashJoinTable hashtable);
/* ----------------------------------------------------------------
* ExecHash
*
* build hash table for hashjoin, doing partitioning if more
* than one batch is required.
* stub for pro forma compliance
* ----------------------------------------------------------------
*/
TupleTableSlot *
ExecHash(HashState *node)
{
elog(ERROR, "Hash node does not support ExecProcNode call convention");
return NULL;
}
/* ----------------------------------------------------------------
* MultiExecHash
*
* build hash table for hashjoin, doing partitioning if more
* than one batch is required.
* ----------------------------------------------------------------
*/
Node *
MultiExecHash(HashState *node)
{
PlanState *outerNode;
List *hashkeys;
@ -50,6 +64,10 @@ ExecHash(HashState *node)
ExprContext *econtext;
uint32 hashvalue;
/* must provide our own instrumentation support */
if (node->ps.instrument)
InstrStartNode(node->ps.instrument);
/*
* get state info from node
*/
@ -70,14 +88,24 @@ ExecHash(HashState *node)
slot = ExecProcNode(outerNode);
if (TupIsNull(slot))
break;
hashtable->hashNonEmpty = true;
hashtable->totalTuples += 1;
/* We have to compute the hash value */
econtext->ecxt_innertuple = slot;
hashvalue = ExecHashGetHashValue(hashtable, econtext, hashkeys);
ExecHashTableInsert(hashtable, ExecFetchSlotTuple(slot), hashvalue);
}
/* We needn't return a tuple slot or anything else */
/* must provide our own instrumentation support */
if (node->ps.instrument)
InstrStopNodeMulti(node->ps.instrument, hashtable->totalTuples);
/*
* We do not return the hash table directly because it's not a subtype
* of Node, and so would violate the MultiExecProcNode API. Instead,
* our parent Hashjoin node is expected to know how to fish it out
* of our node state. Ugly but not really worth cleaning up, since
* Hashjoin knows quite a bit more about Hash besides that.
*/
return NULL;
}
@ -220,7 +248,7 @@ ExecHashTableCreate(Hash *node, List *hashOperators)
hashtable->nbatch_original = nbatch;
hashtable->nbatch_outstart = nbatch;
hashtable->growEnabled = true;
hashtable->hashNonEmpty = false;
hashtable->totalTuples = 0;
hashtable->innerBatchFile = NULL;
hashtable->outerBatchFile = NULL;
hashtable->spaceUsed = 0;