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Diffstat (limited to 'src/backend/executor/nodeSeqscan.c')
-rw-r--r--src/backend/executor/nodeSeqscan.c211
1 files changed, 52 insertions, 159 deletions
diff --git a/src/backend/executor/nodeSeqscan.c b/src/backend/executor/nodeSeqscan.c
index 24de6184010..b953dcd3697 100644
--- a/src/backend/executor/nodeSeqscan.c
+++ b/src/backend/executor/nodeSeqscan.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/executor/nodeSeqscan.c,v 1.23 2000/06/15 04:09:52 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/executor/nodeSeqscan.c,v 1.24 2000/07/12 02:37:04 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -31,8 +31,7 @@
#include "parser/parsetree.h"
static Oid InitScanRelation(SeqScan *node, EState *estate,
- CommonScanState *scanstate, Plan *outerPlan);
-
+ CommonScanState *scanstate);
static TupleTableSlot *SeqNext(SeqScan *node);
/* ----------------------------------------------------------------
@@ -132,25 +131,11 @@ SeqNext(SeqScan *node)
TupleTableSlot *
ExecSeqScan(SeqScan *node)
{
- TupleTableSlot *slot;
- Plan *outerPlan;
-
- S_printf("ExecSeqScan: scanning node: ");
- S_nodeDisplay(node);
-
/* ----------------
- * if there is an outer subplan, get a tuple from it
- * else, scan the relation
+ * use SeqNext as access method
* ----------------
*/
- if ((outerPlan = outerPlan((Plan *) node)) != NULL)
- slot = ExecProcNode(outerPlan, (Plan *) node);
- else
- slot = ExecScan(node, SeqNext);
-
- S1_printf("ExecSeqScan: returned tuple slot: %d\n", slot);
-
- return slot;
+ return ExecScan(node, (ExecScanAccessMtd) SeqNext);
}
/* ----------------------------------------------------------------
@@ -162,7 +147,7 @@ ExecSeqScan(SeqScan *node)
*/
static Oid
InitScanRelation(SeqScan *node, EState *estate,
- CommonScanState *scanstate, Plan *outerPlan)
+ CommonScanState *scanstate)
{
Index relid;
List *rangeTable;
@@ -173,85 +158,57 @@ InitScanRelation(SeqScan *node, EState *estate,
HeapScanDesc currentScanDesc;
RelationInfo *resultRelationInfo;
- if (outerPlan == NULL)
- {
- /* ----------------
- * if the outer node is nil then we are doing a simple
- * sequential scan of a relation...
- *
- * get the relation object id from the relid'th entry
- * in the range table, open that relation and initialize
- * the scan state...
- * ----------------
- */
- relid = node->scanrelid;
- rangeTable = estate->es_range_table;
- rtentry = rt_fetch(relid, rangeTable);
- reloid = rtentry->relid;
- direction = estate->es_direction;
- resultRelationInfo = estate->es_result_relation_info;
-
- ExecOpenScanR(reloid, /* relation */
- 0, /* nkeys */
- NULL, /* scan key */
- 0, /* is index */
- direction,/* scan direction */
- estate->es_snapshot,
- &currentRelation, /* return: rel desc */
- (Pointer *) &currentScanDesc); /* return: scan desc */
-
- scanstate->css_currentRelation = currentRelation;
- scanstate->css_currentScanDesc = currentScanDesc;
-
- ExecAssignScanType(scanstate,
- RelationGetDescr(currentRelation));
- }
- else
- {
- /* ----------------
- * otherwise we are scanning tuples from the
- * outer subplan so we initialize the outer plan
- * and nullify
- * ----------------
- */
- ExecInitNode(outerPlan, estate, (Plan *) node);
-
- node->scanrelid = 0;
- scanstate->css_currentRelation = NULL;
- scanstate->css_currentScanDesc = NULL;
- ExecAssignScanType(scanstate, NULL);
- reloid = InvalidOid;
- }
-
/* ----------------
- * return the relation
+ * get the relation object id from the relid'th entry
+ * in the range table, open that relation and initialize
+ * the scan state...
* ----------------
*/
+ relid = node->scanrelid;
+ rangeTable = estate->es_range_table;
+ rtentry = rt_fetch(relid, rangeTable);
+ reloid = rtentry->relid;
+ direction = estate->es_direction;
+ resultRelationInfo = estate->es_result_relation_info;
+
+ ExecOpenScanR(reloid, /* relation */
+ 0, /* nkeys */
+ NULL, /* scan key */
+ 0, /* is index */
+ direction, /* scan direction */
+ estate->es_snapshot,
+ &currentRelation, /* return: rel desc */
+ (Pointer *) &currentScanDesc); /* return: scan desc */
+
+ scanstate->css_currentRelation = currentRelation;
+ scanstate->css_currentScanDesc = currentScanDesc;
+
+ ExecAssignScanType(scanstate, RelationGetDescr(currentRelation));
+
return reloid;
}
/* ----------------------------------------------------------------
* ExecInitSeqScan
- *
- * old comments
- * Creates the run-time state information for the seqscan node
- * and sets the relation id to contain relevant descriptors.
- *
- * If there is a outer subtree (sort), the outer subtree
- * is initialized and the relation id is set to the descriptors
- * returned by the subtree.
* ----------------------------------------------------------------
*/
bool
ExecInitSeqScan(SeqScan *node, EState *estate, Plan *parent)
{
CommonScanState *scanstate;
- Plan *outerPlan;
Oid reloid;
HeapScanDesc scandesc;
/* ----------------
+ * Once upon a time it was possible to have an outerPlan of a SeqScan,
+ * but not any more.
+ * ----------------
+ */
+ Assert(outerPlan((Plan *) node) == NULL);
+ Assert(innerPlan((Plan *) node) == NULL);
+
+ /* ----------------
* assign the node's execution state
* ----------------
*/
@@ -265,13 +222,11 @@ ExecInitSeqScan(SeqScan *node, EState *estate, Plan *parent)
node->scanstate = scanstate;
/* ----------------
- * Miscellanious initialization
+ * Miscellaneous initialization
*
- * + assign node's base_id
* + create expression context for node
* ----------------
*/
- ExecAssignNodeBaseInfo(estate, &scanstate->cstate, parent);
ExecAssignExprContext(estate, &scanstate->cstate);
#define SEQSCAN_NSLOTS 3
@@ -283,12 +238,10 @@ ExecInitSeqScan(SeqScan *node, EState *estate, Plan *parent)
ExecInitScanTupleSlot(estate, scanstate);
/* ----------------
- * initialize scan relation or outer subplan
+ * initialize scan relation
* ----------------
*/
- outerPlan = outerPlan((Plan *) node);
-
- reloid = InitScanRelation(node, estate, scanstate, outerPlan);
+ reloid = InitScanRelation(node, estate, scanstate);
scandesc = scanstate->css_currentScanDesc;
scanstate->cstate.cs_TupFromTlist = false;
@@ -315,15 +268,12 @@ ExecCountSlotsSeqScan(SeqScan *node)
* ExecEndSeqScan
*
* frees any storage allocated through C routines.
- *| ...and also closes relations and/or shuts down outer subplan
- *| -cim 8/14/89
* ----------------------------------------------------------------
*/
void
ExecEndSeqScan(SeqScan *node)
{
CommonScanState *scanstate;
- Plan *outerPlan;
/* ----------------
* get information from node
@@ -341,6 +291,7 @@ ExecEndSeqScan(SeqScan *node)
* ----------------
*/
ExecFreeProjectionInfo(&scanstate->cstate);
+ ExecFreeExprContext(&scanstate->cstate);
/* ----------------
* close scan relation
@@ -349,13 +300,6 @@ ExecEndSeqScan(SeqScan *node)
ExecCloseR((Plan *) node);
/* ----------------
- * clean up outer subtree (does nothing if there is no outerPlan)
- * ----------------
- */
- outerPlan = outerPlan((Plan *) node);
- ExecEndNode(outerPlan, (Plan *) node);
-
- /* ----------------
* clean out the tuple table
* ----------------
*/
@@ -367,6 +311,7 @@ ExecEndSeqScan(SeqScan *node)
* Join Support
* ----------------------------------------------------------------
*/
+
/* ----------------------------------------------------------------
* ExecSeqReScan
*
@@ -378,7 +323,6 @@ ExecSeqReScan(SeqScan *node, ExprContext *exprCtxt, Plan *parent)
{
CommonScanState *scanstate;
EState *estate;
- Plan *outerPlan;
Relation rel;
HeapScanDesc scan;
ScanDirection direction;
@@ -386,28 +330,18 @@ ExecSeqReScan(SeqScan *node, ExprContext *exprCtxt, Plan *parent)
scanstate = node->scanstate;
estate = node->plan.state;
- if ((outerPlan = outerPlan((Plan *) node)) != NULL)
- {
- /* we are scanning a subplan */
- outerPlan = outerPlan((Plan *) node);
- ExecReScan(outerPlan, exprCtxt, parent);
- }
- else
-/* otherwise, we are scanning a relation */
+ /* If this is re-scanning of PlanQual ... */
+ if (estate->es_evTuple != NULL &&
+ estate->es_evTuple[node->scanrelid - 1] != NULL)
{
- /* If this is re-scanning of PlanQual ... */
- if (estate->es_evTuple != NULL &&
- estate->es_evTuple[node->scanrelid - 1] != NULL)
- {
- estate->es_evTupleNull[node->scanrelid - 1] = false;
- return;
- }
- rel = scanstate->css_currentRelation;
- scan = scanstate->css_currentScanDesc;
- direction = estate->es_direction;
- scan = ExecReScanR(rel, scan, direction, 0, NULL);
- scanstate->css_currentScanDesc = scan;
+ estate->es_evTupleNull[node->scanrelid - 1] = false;
+ return;
}
+ rel = scanstate->css_currentRelation;
+ scan = scanstate->css_currentScanDesc;
+ direction = estate->es_direction;
+ scan = ExecReScanR(rel, scan, direction, 0, NULL);
+ scanstate->css_currentScanDesc = scan;
}
/* ----------------------------------------------------------------
@@ -420,33 +354,11 @@ void
ExecSeqMarkPos(SeqScan *node)
{
CommonScanState *scanstate;
- Plan *outerPlan;
HeapScanDesc scan;
scanstate = node->scanstate;
-
- /* ----------------
- * if we are scanning a subplan then propagate
- * the ExecMarkPos() request to the subplan
- * ----------------
- */
- outerPlan = outerPlan((Plan *) node);
- if (outerPlan)
- {
- ExecMarkPos(outerPlan);
- return;
- }
-
- /* ----------------
- * otherwise we are scanning a relation so mark the
- * position using the access methods..
- *
- * ----------------
- */
scan = scanstate->css_currentScanDesc;
heap_markpos(scan);
-
- return;
}
/* ----------------------------------------------------------------
@@ -459,28 +371,9 @@ void
ExecSeqRestrPos(SeqScan *node)
{
CommonScanState *scanstate;
- Plan *outerPlan;
HeapScanDesc scan;
scanstate = node->scanstate;
-
- /* ----------------
- * if we are scanning a subplan then propagate
- * the ExecRestrPos() request to the subplan
- * ----------------
- */
- outerPlan = outerPlan((Plan *) node);
- if (outerPlan)
- {
- ExecRestrPos(outerPlan);
- return;
- }
-
- /* ----------------
- * otherwise we are scanning a relation so restore the
- * position using the access methods..
- * ----------------
- */
scan = scanstate->css_currentScanDesc;
heap_restrpos(scan);
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-01 11:24:54 +0000