コード例 #1
0
/* ----------------------------------------------------------------
 *		ExecBitmapHeapReScan(node)
 * ----------------------------------------------------------------
 */
void
ExecBitmapHeapReScan(BitmapHeapScanState *node, ExprContext *exprCtxt)
{
	EState	   *estate;
	Index		scanrelid;

	estate = node->ss.ps.state;
	scanrelid = ((BitmapHeapScan *) node->ss.ps.plan)->scan.scanrelid;

	/*
	 * If we are being passed an outer tuple, link it into the "regular"
	 * per-tuple econtext for possible qual eval.
	 */
	if (exprCtxt != NULL)
	{
		ExprContext *stdecontext;

		stdecontext = node->ss.ps.ps_ExprContext;
		stdecontext->ecxt_outertuple = exprCtxt->ecxt_outertuple;
	}

	/* If this is re-scanning of PlanQual ... */
	if (estate->es_evTuple != NULL &&
		estate->es_evTuple[scanrelid - 1] != NULL)
	{
		estate->es_evTupleNull[scanrelid - 1] = false;
	}

	/* rescan to release any page pin */
	heap_rescan(node->ss.ss_currentScanDesc, NULL);

	/* undo bogus "seq scan" count (see notes in ExecInitBitmapHeapScan) */
	pgstat_discount_heap_scan(&node->ss.ss_currentScanDesc->rs_pgstat_info);

	if (node->tbm)
		tbm_free(node->tbm);
	node->tbm = NULL;
	node->tbmres = NULL;

	if (node->odbm)
		odbm_free(node->odbm);
	node->odbm = NULL;

	/*
	 * Always rescan the input immediately, to ensure we can pass down any
	 * outer tuple that might be used in index quals.
	 */
	ExecReScan(outerPlanState(node), exprCtxt);
}
コード例 #2
0
/* ----------------------------------------------------------------
 *		ExecInitBitmapHeapScan
 *
 *		Initializes the scan's state information.
 * ----------------------------------------------------------------
 */
BitmapHeapScanState *
ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags)
{
	BitmapHeapScanState *scanstate;
	Relation	currentRelation;

	/* check for unsupported flags */
	Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));

	/*
	 * Assert caller didn't ask for an unsafe snapshot --- see comments at
	 * head of file.
	 */
	Assert(IsMVCCSnapshot(estate->es_snapshot));

	/*
	 * create state structure
	 */
	scanstate = makeNode(BitmapHeapScanState);
	scanstate->ss.ps.plan = (Plan *) node;
	scanstate->ss.ps.state = estate;

	scanstate->tbm = NULL;
	scanstate->tbmres = NULL;

	/*
	 * Miscellaneous initialization
	 *
	 * create expression context for node
	 */
	ExecAssignExprContext(estate, &scanstate->ss.ps);

	scanstate->ss.ps.ps_TupFromTlist = false;

	/*
	 * initialize child expressions
	 */
	scanstate->ss.ps.targetlist = (List *)
		ExecInitExpr((Expr *) node->scan.plan.targetlist,
					 (PlanState *) scanstate);
	scanstate->ss.ps.qual = (List *)
		ExecInitExpr((Expr *) node->scan.plan.qual,
					 (PlanState *) scanstate);
	scanstate->bitmapqualorig = (List *)
		ExecInitExpr((Expr *) node->bitmapqualorig,
					 (PlanState *) scanstate);

#define BITMAPHEAPSCAN_NSLOTS 2

	/*
	 * tuple table initialization
	 */
	ExecInitResultTupleSlot(estate, &scanstate->ss.ps);
	ExecInitScanTupleSlot(estate, &scanstate->ss);

	/*
	 * open the base relation and acquire appropriate lock on it.
	 */
	currentRelation = ExecOpenScanRelation(estate, node->scan.scanrelid);

	scanstate->ss.ss_currentRelation = currentRelation;

	/*
	 * Even though we aren't going to do a conventional seqscan, it is useful
	 * to create a HeapScanDesc --- this checks the relation size and sets up
	 * statistical infrastructure for us.
	 */
	scanstate->ss.ss_currentScanDesc = heap_beginscan(currentRelation,
													  estate->es_snapshot,
													  0,
													  NULL);

	/*
	 * One problem is that heap_beginscan counts a "sequential scan" start,
	 * when we actually aren't doing any such thing.  Reverse out the added
	 * scan count.	(Eventually we may want to count bitmap scans separately.)
	 */
	pgstat_discount_heap_scan(&scanstate->ss.ss_currentScanDesc->rs_pgstat_info);

	/*
	 * get the scan type from the relation descriptor.
	 */
	ExecAssignScanType(&scanstate->ss, RelationGetDescr(currentRelation));

	/*
	 * Initialize result tuple type and projection info.
	 */
	ExecAssignResultTypeFromTL(&scanstate->ss.ps);
	ExecAssignScanProjectionInfo(&scanstate->ss);

	/*
	 * initialize child nodes
	 *
	 * We do this last because the child nodes will open indexscans on our
	 * relation's indexes, and we want to be sure we have acquired a lock on
	 * the relation first.
	 */
	outerPlanState(scanstate) = ExecInitNode(outerPlan(node), estate, eflags);

	/*
	 * all done.
	 */
	return scanstate;
}
コード例 #3
0
/* ----------------------------------------------------------------
 *		ExecInitBitmapHeapScan
 *
 *		Initializes the scan's state information.
 * ----------------------------------------------------------------
 */
BitmapHeapScanState *
ExecInitBitmapHeapScan(BitmapHeapScan *node, EState *estate, int eflags)
{
	BitmapHeapScanState *scanstate;
	RangeTblEntry *rtentry;
	Index		relid;
	Oid			reloid;
	Relation	currentRelation;

  /* check for unsupported flags */
  Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
	/*
	 * create state structure
	 */
	scanstate = makeNode(BitmapHeapScanState);
	scanstate->ss.ps.plan = (Plan *) node;
	scanstate->ss.ps.state = estate;

	scanstate->tbm = NULL;
	scanstate->tbmres = NULL;

	/*
	 * Miscellaneous initialization
	 *
	 * create expression context for node
	 */
	ExecAssignExprContext(estate, &scanstate->ss.ps);

	/*
	 * initialize child expressions
	 */
	scanstate->ss.ps.targetlist = (List *)
		ExecInitExpr((Expr *) node->scan.plan.targetlist,
					 (PlanState *) scanstate);
	scanstate->ss.ps.qual = (List *)
		ExecInitExpr((Expr *) node->scan.plan.qual,
					 (PlanState *) scanstate);
	scanstate->bitmapqualorig = (List *)
		ExecInitExpr((Expr *) node->bitmapqualorig,
					 (PlanState *) scanstate);

#define BITMAPHEAPSCAN_NSLOTS 2

	/*
	 * tuple table initialization
	 */
	ExecInitResultTupleSlot(estate, &scanstate->ss.ps);
	ExecInitScanTupleSlot(estate, &scanstate->ss);

	CXT1_printf("ExecInitBitmapHeapScan: context is %d\n", CurrentMemoryContext);

	/*
	 * open the base relation and acquire AccessShareLock on it.
	 */
	relid = node->scan.scanrelid;
	rtentry = rt_fetch(relid, estate->es_range_table);
	reloid = rtentry->relid;

	currentRelation = heap_open(reloid, AccessShareLock);

	scanstate->ss.ss_currentRelation = currentRelation;

	/*
	 * Even though we aren't going to do a conventional seqscan, it is useful
	 * to create a HeapScanDesc --- this checks the relation size and sets up
	 * statistical infrastructure for us.
	 */
	scanstate->ss.ss_currentScanDesc = heap_beginscan(currentRelation,
													  estate->es_snapshot,
													  0,
													  NULL);

	/*
	 * One problem is that heap_beginscan counts a "sequential scan" start,
	 * when we actually aren't doing any such thing.  Reverse out the added
	 * scan count.	(Eventually we may want to count bitmap scans separately.)
	 */
	pgstat_discount_heap_scan(&scanstate->ss.ss_currentScanDesc->rs_pgstat_info);

	/*
	 * get the scan type from the relation descriptor.
	 */
	ExecAssignScanType(&scanstate->ss, RelationGetDescr(currentRelation), false);

	/*
	 * Initialize result tuple type and projection info.
	 */
	ExecAssignResultTypeFromTL(&scanstate->ss.ps);
	ExecAssignScanProjectionInfo(&scanstate->ss);

	/*
	 * initialize child nodes
	 *
	 * We do this last because the child nodes will open indexscans on our
	 * relation's indexes, and we want to be sure we have acquired a lock
	 * on the relation first.
	 */
	outerPlanState(scanstate) = ExecInitNode(outerPlan(node), estate, eflags);

	if (IsA(outerPlan(node), BitmapIndexScan))
		node->inmem = 
			(((BitmapIndexScan*)outerPlan(node))->indexam != 
			 BITMAP_AM_OID);
	else if (IsA(outerPlan(node), BitmapAnd))
		node->inmem = ((BitmapAnd*)outerPlan(node))->inmem;
	else if (IsA(outerPlan(node), BitmapOr))
		node->inmem = ((BitmapOr*)outerPlan(node))->inmem;
	else
		node->inmem = true;

	/*
	 * all done.
	 */
	return scanstate;
}