diff options
Diffstat (limited to 'src/backend/executor/execAmi.c')
| -rw-r--r-- | src/backend/executor/execAmi.c | 232 |
1 files changed, 1 insertions, 231 deletions
diff --git a/src/backend/executor/execAmi.c b/src/backend/executor/execAmi.c index af0e190d396..e7a335916bd 100644 --- a/src/backend/executor/execAmi.c +++ b/src/backend/executor/execAmi.c @@ -6,25 +6,12 @@ * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: execAmi.c,v 1.60 2001/10/25 05:49:27 momjian Exp $ + * $Id: execAmi.c,v 1.61 2002/02/19 20:11:13 tgl Exp $ * *------------------------------------------------------------------------- */ -/* - * INTERFACE ROUTINES - * - * ExecOpenScanR \ / amopen - * ExecBeginScan \ / ambeginscan - * ExecCloseR \ / amclose - * ExecInsert \ executor interface / aminsert - * ExecReScanR / to access methods \ amrescan - * ExecMarkPos / \ ammarkpos - * ExecRestrPos / \ amrestpos - */ - #include "postgres.h" - #include "access/genam.h" #include "access/heapam.h" #include "catalog/heap.h" @@ -50,202 +37,6 @@ #include "executor/nodeSubqueryscan.h" #include "executor/nodeUnique.h" -static Pointer ExecBeginScan(Relation relation, int nkeys, ScanKey skeys, - bool isindex, ScanDirection dir, Snapshot snapshot); - -/* ---------------------------------------------------------------- - * 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 a heap relation. - * Returns the relation as(relDesc scanDesc) - * ---------------------------------------------------------------- - */ -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 - */ - - /* - * Open the relation with the correct call depending on whether this - * is a heap relation or an index relation. - * - * For a table, acquire AccessShareLock for the duration of the query - * execution. For indexes, acquire no lock here; the index machinery - * does its own locks and unlocks. (We rely on having some kind of - * lock on the parent table to ensure the index won't go away!) - */ - if (isindex) - relation = index_open(relOid); - else - relation = heap_open(relOid, AccessShareLock); - - scanDesc = ExecBeginScan(relation, - nkeys, - skeys, - isindex, - dir, - snapshot); - - if (returnRelation != NULL) - *returnRelation = relation; - if (scanDesc != NULL) - *returnScanDesc = scanDesc; -} - -/* ---------------------------------------------------------------- - * 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; - - /* - * 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 node. - * Also closes index relations and scans for index scans. - * ---------------------------------------------------------------- - */ -void -ExecCloseR(Plan *node) -{ - CommonScanState *state; - Relation relation; - HeapScanDesc scanDesc; - - /* - * get state for node and shut down the heap scan, if any - */ - switch (nodeTag(node)) - { - case T_SeqScan: - state = ((SeqScan *) node)->scanstate; - break; - - case T_IndexScan: - state = ((IndexScan *) node)->scan.scanstate; - break; - - case T_TidScan: - state = ((TidScan *) node)->scan.scanstate; - break; - - default: - elog(DEBUG, "ExecCloseR: not a scan node!"); - return; - } - - relation = state->css_currentRelation; - scanDesc = state->css_currentScanDesc; - - if (scanDesc != NULL) - heap_endscan(scanDesc); - - /* - * if this is an index scan then we have to take care of the index - * relations as well. - */ - if (IsA(node, IndexScan)) - { - IndexScan *iscan = (IndexScan *) node; - IndexScanState *indexstate = iscan->indxstate; - int numIndices; - RelationPtr indexRelationDescs; - IndexScanDescPtr indexScanDescs; - int i; - - numIndices = indexstate->iss_NumIndices; - indexRelationDescs = indexstate->iss_RelationDescs; - indexScanDescs = indexstate->iss_ScanDescs; - - for (i = 0; i < numIndices; i++) - { - /* - * shut down each of the index scans and close each of the - * index relations - */ - if (indexScanDescs[i] != NULL) - index_endscan(indexScanDescs[i]); - - if (indexRelationDescs[i] != NULL) - index_close(indexRelationDescs[i]); - } - } - - /* - * Finally, close the heap relation. - * - * Currently, we do not release the AccessShareLock acquired by - * ExecOpenScanR. This lock should be held till end of transaction. - * (There is a faction that considers this too much locking, however.) - */ - if (relation != NULL) - heap_close(relation, NoLock); -} /* ---------------------------------------------------------------- * ExecReScan @@ -375,27 +166,6 @@ ExecReScan(Plan *node, ExprContext *exprCtxt, Plan *parent) } /* ---------------------------------------------------------------- - * 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. |