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postgresql/src/backend/executor/execAmi.c

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/*-------------------------------------------------------------------------
*
* execAmi.c--
* miscellanious executor access method routines
*
* Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/execAmi.c,v 1.25 1998/09/01 04:28:13 momjian Exp $
*
*-------------------------------------------------------------------------
*/
/*
* INTERFACE ROUTINES
*
* ExecOpenScanR \ / amopen
* ExecBeginScan \ / ambeginscan
* ExecCloseR \ / amclose
* ExecInsert \ executor interface / aminsert
* ExecReScanNode / to access methods \ amrescan
* ExecReScanR / \ amrescan
* ExecMarkPos / \ ammarkpos
* ExecRestrPos / \ amrestpos
*
* ExecCreatR function to create temporary relations
*
*/
#include <stdio.h> /* for sprintf() */
#include "postgres.h"
#include "executor/executor.h"
#include "storage/smgr.h"
#include "utils/mcxt.h"
#include "executor/nodeSeqscan.h"
#include "executor/nodeIndexscan.h"
#include "executor/nodeSort.h"
#include "executor/nodeTee.h"
#include "executor/nodeMaterial.h"
#include "executor/nodeNestloop.h"
#include "executor/nodeHashjoin.h"
#include "executor/nodeHash.h"
#include "executor/nodeAgg.h"
#include "executor/nodeGroup.h"
#include "executor/nodeResult.h"
#include "executor/nodeUnique.h"
#include "executor/nodeMergejoin.h"
#include "executor/nodeAppend.h"
#include "executor/nodeSubplan.h"
#include "executor/execdebug.h"
#include "optimizer/internal.h" /* for _TEMP_RELATION_ID_ */
#include "access/genam.h"
#include "access/heapam.h"
#include "catalog/heap.h"
static Pointer ExecBeginScan(Relation relation, int nkeys, ScanKey skeys,
bool isindex, ScanDirection dir, Snapshot snapshot);
static Relation ExecOpenR(Oid relationOid, bool isindex);
/* ----------------------------------------------------------------
* ExecOpenScanR
*
* old comments:
* Parameters:
* relation -- relation to be opened and scanned.
* nkeys -- number of keys
* skeys -- keys to restrict scanning
* isindex -- if this is true, the relation is the relid of
* an index relation, else it is an index into the
* range table.
* Returns the relation as(relDesc scanDesc)
* If this structure is changed, need to modify the access macros
* defined in execInt.h.
* ----------------------------------------------------------------
*/
void
ExecOpenScanR(Oid relOid,
int nkeys,
ScanKey skeys,
bool isindex,
ScanDirection dir,
Snapshot snapshot,
Relation *returnRelation, /* return */
Pointer *returnScanDesc) /* return */
{
Relation relation;
Pointer scanDesc;
/* ----------------
* note: scanDesc returned by ExecBeginScan can be either
* a HeapScanDesc or an IndexScanDesc so for now we
* make it a Pointer. There should be a better scan
* abstraction someday -cim 9/9/89
* ----------------
*/
relation = ExecOpenR(relOid, isindex);
scanDesc = ExecBeginScan(relation,
nkeys,
skeys,
isindex,
dir,
snapshot);
if (returnRelation != NULL)
*returnRelation = relation;
if (scanDesc != NULL)
*returnScanDesc = scanDesc;
}
/* ----------------------------------------------------------------
* ExecOpenR
*
* returns a relation descriptor given an object id.
* ----------------------------------------------------------------
*/
static Relation
ExecOpenR(Oid relationOid, bool isindex)
{
Relation relation;
relation = (Relation) NULL;
/* ----------------
* open the relation with the correct call depending
* on whether this is a heap relation or an index relation.
* ----------------
*/
if (isindex)
relation = index_open(relationOid);
else
relation = heap_open(relationOid);
if (relation == NULL)
elog(DEBUG, "ExecOpenR: relation == NULL, heap_open failed.");
return relation;
}
/* ----------------------------------------------------------------
* ExecBeginScan
*
* beginscans a relation in current direction.
*
* XXX fix parameters to AMbeginscan (and btbeginscan)
* currently we need to pass a flag stating whether
* or not the scan should begin at an endpoint of
* the relation.. Right now we always pass false
* -cim 9/14/89
* ----------------------------------------------------------------
*/
static Pointer
ExecBeginScan(Relation relation,
int nkeys,
ScanKey skeys,
bool isindex,
ScanDirection dir,
Snapshot snapshot)
{
Pointer scanDesc;
scanDesc = NULL;
/* ----------------
* open the appropriate type of scan.
*
* Note: ambeginscan()'s second arg is a boolean indicating
* that the scan should be done in reverse.. That is,
* if you pass it true, then the scan is backward.
* ----------------
*/
if (isindex)
{
scanDesc = (Pointer) index_beginscan(relation,
false, /* see above comment */
nkeys,
skeys);
}
else
{
scanDesc = (Pointer) heap_beginscan(relation,
ScanDirectionIsBackward(dir),
snapshot,
nkeys,
skeys);
}
if (scanDesc == NULL)
elog(DEBUG, "ExecBeginScan: scanDesc = NULL, heap_beginscan failed.");
return scanDesc;
}
/* ----------------------------------------------------------------
* ExecCloseR
*
* closes the relation and scan descriptor for a scan or sort
* node. Also closes index relations and scans for index scans.
*
* old comments
* closes the relation indicated in 'relID'
* ----------------------------------------------------------------
*/
void
ExecCloseR(Plan *node)
{
CommonScanState *state;
Relation relation;
HeapScanDesc scanDesc;
/* ----------------
* shut down the heap scan and close the heap relation
* ----------------
*/
switch (nodeTag(node))
{
case T_SeqScan:
state = ((SeqScan *) node)->scanstate;
break;
case T_IndexScan:
state = ((IndexScan *) node)->scan.scanstate;
break;
case T_Material:
state = &(((Material *) node)->matstate->csstate);
break;
case T_Sort:
state = &(((Sort *) node)->sortstate->csstate);
break;
case T_Agg:
state = &(((Agg *) node)->aggstate->csstate);
break;
default:
elog(DEBUG, "ExecCloseR: not a scan, material, or sort node!");
return;
}
relation = state->css_currentRelation;
scanDesc = state->css_currentScanDesc;
if (scanDesc != NULL)
heap_endscan(scanDesc);
if (relation != NULL)
heap_close(relation);
/* ----------------
* if this is an index scan then we have to take care
* of the index relations as well..
* ----------------
*/
if (nodeTag(node) == T_IndexScan)
{
IndexScan *iscan = (IndexScan *) node;
IndexScanState *indexstate;
int numIndices;
RelationPtr indexRelationDescs;
IndexScanDescPtr indexScanDescs;
int i;
indexstate = iscan->indxstate;
numIndices = indexstate->iss_NumIndices;
indexRelationDescs = indexstate->iss_RelationDescs;
indexScanDescs = indexstate->iss_ScanDescs;
for (i = 0; i < numIndices; i++)
{
/* ----------------
* shut down each of the scans and
* close each of the index relations
* ----------------
*/
if (indexScanDescs[i] != NULL)
index_endscan(indexScanDescs[i]);
if (indexRelationDescs[i] != NULL)
index_close(indexRelationDescs[i]);
}
}
}
/* ----------------------------------------------------------------
* ExecReScan
*
* XXX this should be extended to cope with all the node types..
*
* takes the new expression context as an argument, so that
* index scans needn't have their scan keys updated separately
* - marcel 09/20/94
* ----------------------------------------------------------------
*/
void
ExecReScan(Plan *node, ExprContext *exprCtxt, Plan *parent)
{
if (node->chgParam != NULL) /* Wow! */
{
List *lst;
foreach(lst, node->initPlan)
{
Plan *splan = ((SubPlan *) lfirst(lst))->plan;
if (splan->extParam != NULL) /* don't care about child
* locParam */
SetChangedParamList(splan, node->chgParam);
if (splan->chgParam != NULL)
ExecReScanSetParamPlan((SubPlan *) lfirst(lst), node);
}
foreach(lst, node->subPlan)
{
Plan *splan = ((SubPlan *) lfirst(lst))->plan;
if (splan->extParam != NULL)
SetChangedParamList(splan, node->chgParam);
}
/* Well. Now set chgParam for left/right trees. */
if (node->lefttree != NULL)
SetChangedParamList(node->lefttree, node->chgParam);
if (node->righttree != NULL)
SetChangedParamList(node->righttree, node->chgParam);
}
switch (nodeTag(node))
{
case T_SeqScan:
ExecSeqReScan((SeqScan *) node, exprCtxt, parent);
break;
case T_IndexScan:
ExecIndexReScan((IndexScan *) node, exprCtxt, parent);
break;
case T_Material:
ExecMaterialReScan((Material *) node, exprCtxt, parent);
break;
case T_NestLoop:
ExecReScanNestLoop((NestLoop *) node, exprCtxt, parent);
break;
case T_HashJoin:
ExecReScanHashJoin((HashJoin *) node, exprCtxt, parent);
break;
case T_Hash:
ExecReScanHash((Hash *) node, exprCtxt, parent);
break;
case T_Agg:
ExecReScanAgg((Agg *) node, exprCtxt, parent);
break;
case T_Group:
ExecReScanGroup((Group *) node, exprCtxt, parent);
break;
case T_Result:
ExecReScanResult((Result *) node, exprCtxt, parent);
break;
case T_Unique:
ExecReScanUnique((Unique *) node, exprCtxt, parent);
break;
case T_Sort:
ExecReScanSort((Sort *) node, exprCtxt, parent);
break;
case T_MergeJoin:
ExecReScanMergeJoin((MergeJoin *) node, exprCtxt, parent);
break;
case T_Append:
ExecReScanAppend((Append *) node, exprCtxt, parent);
break;
/*
* Tee is never used
case T_Tee:
ExecTeeReScan((Tee *) node, exprCtxt, parent);
break;
*/
default:
elog(ERROR, "ExecReScan: node type %u not supported", nodeTag(node));
return;
}
if (node->chgParam != NULL)
{
freeList(node->chgParam);
node->chgParam = NULL;
}
}
/* ----------------------------------------------------------------
* ExecReScanR
*
* XXX this does not do the right thing with indices yet.
* ----------------------------------------------------------------
*/
HeapScanDesc
ExecReScanR(Relation relDesc, /* LLL relDesc unused */
HeapScanDesc scanDesc,
ScanDirection direction,
int nkeys, /* LLL nkeys unused */
ScanKey skeys)
{
if (scanDesc != NULL)
heap_rescan(scanDesc, /* scan desc */
ScanDirectionIsBackward(direction), /* backward flag */
skeys); /* scan keys */
return scanDesc;
}
/* ----------------------------------------------------------------
* ExecMarkPos
*
* Marks the current scan position.
*
* XXX Needs to be extended to include all the node types.
* ----------------------------------------------------------------
*/
void
ExecMarkPos(Plan *node)
{
switch (nodeTag(node))
{
case T_SeqScan:
ExecSeqMarkPos((SeqScan *) node);
break;
case T_IndexScan:
ExecIndexMarkPos((IndexScan *) node);
break;
case T_Sort:
ExecSortMarkPos((Sort *) node);
break;
default:
elog(DEBUG, "ExecMarkPos: node type %u not supported", nodeTag(node));
break;
}
return;
}
/* ----------------------------------------------------------------
* ExecRestrPos
*
* restores the scan position previously saved with ExecMarkPos()
* ----------------------------------------------------------------
*/
void
ExecRestrPos(Plan *node)
{
switch (nodeTag(node))
{
case T_SeqScan:
ExecSeqRestrPos((SeqScan *) node);
return;
case T_IndexScan:
ExecIndexRestrPos((IndexScan *) node);
return;
case T_Sort:
ExecSortRestrPos((Sort *) node);
return;
default:
elog(DEBUG, "ExecRestrPos: node type %u not supported", nodeTag(node));
return;
}
}
/* ----------------------------------------------------------------
* ExecCreatR
*
* old comments
* Creates a relation.
*
* Parameters:
* attrType -- type information on the attributes.
* accessMtd -- access methods used to access the created relation.
* relation -- optional. Either an index to the range table or
* negative number indicating a temporary relation.
* A temporary relation is assume if this field is absent.
* ----------------------------------------------------------------
*/
Relation
ExecCreatR(TupleDesc tupType,
Oid relationOid)
{
Relation relDesc;
EU3_printf("ExecCreatR: %s type=%d oid=%d\n",
"entering: ", tupType, relationOid);
CXT1_printf("ExecCreatR: context is %d\n", CurrentMemoryContext);
relDesc = NULL;
if (relationOid == _TEMP_RELATION_ID_)
{
/* ----------------
* create a temporary relation
* (currently the planner always puts a _TEMP_RELATION_ID
* in the relation argument so we expect this to be the case although
* it's possible that someday we'll get the name from
* from the range table.. -cim 10/12/89)
* ----------------
*/
/*
sprintf(tempname, "temp_%d.%d", getpid(), tmpcnt++);
EU1_printf("ExecCreatR: attempting to create %s\n", tempname);
*/
/*
* heap_create creates a name if the argument to heap_create is
* '\0 '
*/
relDesc = heap_create("", tupType);
}
else
{
/* ----------------
* use a relation from the range table
* ----------------
*/
elog(DEBUG, "ExecCreatR: %s",
"stuff using range table id's is not functional");
}
if (relDesc == NULL)
elog(DEBUG, "ExecCreatR: failed to create relation.");
EU1_printf("ExecCreatR: returning relDesc=%d\n", relDesc);
return relDesc;
}
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