Postgres95 1.01 Distribution - Virgin SourcesPG95-1_01

1 files changed, 439 insertions, 0 deletions

diff --git a/src/backend/executor/execAmi.c b/src/backend/executor/execAmi.c
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index 00000000000..08d3e70d8b9
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+++ b/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 1.1.1.1 1996/07/09 06:21:24 scrappy 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 "executor/executor.h"
+#include "storage/smgr.h"
+#include "executor/nodeSeqscan.h"
+#include "executor/nodeIndexscan.h"
+#include "executor/nodeSort.h"
+#include "executor/nodeTee.h"
+#include "optimizer/internal.h" /* for _TEMP_RELATION_ID_ */
+
+/* ----------------------------------------------------------------
+ *   	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,
+	      TimeQual timeRange,
+	      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,
+			     timeRange);
+    
+    if (returnRelation != NULL)
+	*returnRelation = relation;
+    if (scanDesc != NULL)
+	*returnScanDesc = scanDesc;
+}
+ 
+/* ----------------------------------------------------------------
+ *	ExecOpenR
+ *
+ *	returns a relation descriptor given an object id.
+ * ----------------------------------------------------------------
+ */
+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
+ * ----------------------------------------------------------------
+ */
+Pointer
+ExecBeginScan(Relation relation,
+	      int nkeys,
+	      ScanKey skeys,
+	      bool isindex,
+	      ScanDirection dir,
+	      TimeQual time_range)
+{
+    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),
+					    time_range,
+					    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)
+{
+    switch(nodeTag(node)) {
+    case T_SeqScan:
+	ExecSeqReScan((SeqScan *) node, exprCtxt, parent);
+	return;
+    
+    case T_IndexScan:
+	ExecIndexReScan((IndexScan *) node, exprCtxt, parent);
+	return;
+
+    case T_Material:
+	/* the first call to ExecReScan should have no effect because
+	 * everything is initialized properly already.  the following
+	 * calls will be handled by ExecSeqReScan() because the nodes
+	 * below the Material node have already been materialized into
+	 * a temp relation.
+	 */
+	return;
+
+    case T_Tee:
+	ExecTeeReScan((Tee*) node, exprCtxt, parent);
+	break;
+
+    default:
+	elog(WARN, "ExecReScan: not a seqscan or indexscan node.");
+	return;
+    }
+}
+ 
+/* ----------------------------------------------------------------
+ *   	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: unsupported node type"); */
+	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 not supported"); */
+	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 is this field is absent.
+ * ----------------------------------------------------------------
+ */
+
+Relation
+ExecCreatR(TupleDesc tupType,
+	   Oid relationOid)
+{
+    Relation 	relDesc;
+
+    EU4_printf("ExecCreatR: %s numatts=%d type=%d oid=%d\n",
+	       "entering: ", numberAttributes, 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_creatr creates a name if the argument to heap_creatr is '\0 ' */
+	relDesc = heap_creatr("",
+			      DEFAULT_SMGR,
+			      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;
+}
+