diff options
Diffstat (limited to 'src/backend/executor/nodeSeqscan.c')
| -rw-r--r-- | src/backend/executor/nodeSeqscan.c | 108 |
1 files changed, 46 insertions, 62 deletions
diff --git a/src/backend/executor/nodeSeqscan.c b/src/backend/executor/nodeSeqscan.c index d879cee7a75..4e22845a11f 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 1.28 2001/03/22 03:59:29 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/executor/nodeSeqscan.c,v 1.29 2001/03/22 06:16:13 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -54,9 +54,8 @@ SeqNext(SeqScan *node) ScanDirection direction; TupleTableSlot *slot; - /* ---------------- - * get information from the estate and scan state - * ---------------- + /* + * get information from the estate and scan state */ estate = node->plan.state; scanstate = node->scanstate; @@ -91,21 +90,19 @@ SeqNext(SeqScan *node) return (slot); } - /* ---------------- - * get the next tuple from the access methods - * ---------------- + /* + * get the next tuple from the access methods */ tuple = heap_getnext(scandesc, ScanDirectionIsBackward(direction)); - /* ---------------- - * save the tuple and the buffer returned to us by the access methods - * in our scan tuple slot and return the slot. Note: we pass 'false' - * because tuples returned by heap_getnext() are pointers onto - * disk pages and were not created with palloc() and so should not - * be pfree()'d. Note also that ExecStoreTuple will increment the - * refcount of the buffer; the refcount will not be dropped until - * the tuple table slot is cleared. - * ---------------- + /* + * save the tuple and the buffer returned to us by the access methods + * in our scan tuple slot and return the slot. Note: we pass 'false' + * because tuples returned by heap_getnext() are pointers onto disk + * pages and were not created with palloc() and so should not be + * pfree()'d. Note also that ExecStoreTuple will increment the + * refcount of the buffer; the refcount will not be dropped until the + * tuple table slot is cleared. */ slot = ExecStoreTuple(tuple,/* tuple to store */ @@ -130,9 +127,9 @@ SeqNext(SeqScan *node) TupleTableSlot * ExecSeqScan(SeqScan *node) { - /* ---------------- - * use SeqNext as access method - * ---------------- + + /* + * use SeqNext as access method */ return ExecScan(node, (ExecScanAccessMtd) SeqNext); } @@ -156,11 +153,9 @@ InitScanRelation(SeqScan *node, EState *estate, Relation currentRelation; HeapScanDesc currentScanDesc; - /* ---------------- - * get the relation object id from the relid'th entry - * in the range table, open that relation and initialize - * the scan state... - * ---------------- + /* + * 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; @@ -197,55 +192,49 @@ ExecInitSeqScan(SeqScan *node, EState *estate, Plan *parent) Oid reloid; HeapScanDesc scandesc; - /* ---------------- - * Once upon a time it was possible to have an outerPlan of a SeqScan, - * but not any more. - * ---------------- + /* + * 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 - * ---------------- + /* + * assign the node's execution state */ node->plan.state = estate; - /* ---------------- - * create new CommonScanState for node - * ---------------- + /* + * create new CommonScanState for node */ scanstate = makeNode(CommonScanState); node->scanstate = scanstate; - /* ---------------- - * Miscellaneous initialization + /* + * Miscellaneous initialization * - * + create expression context for node - * ---------------- + * create expression context for node */ ExecAssignExprContext(estate, &scanstate->cstate); #define SEQSCAN_NSLOTS 3 - /* ---------------- - * tuple table initialization - * ---------------- + + /* + * tuple table initialization */ ExecInitResultTupleSlot(estate, &scanstate->cstate); ExecInitScanTupleSlot(estate, scanstate); - /* ---------------- - * initialize scan relation - * ---------------- + /* + * initialize scan relation */ reloid = InitScanRelation(node, estate, scanstate); scandesc = scanstate->css_currentScanDesc; scanstate->cstate.cs_TupFromTlist = false; - /* ---------------- - * initialize tuple type - * ---------------- + /* + * initialize tuple type */ ExecAssignResultTypeFromTL((Plan *) node, &scanstate->cstate); ExecAssignProjectionInfo((Plan *) node, &scanstate->cstate); @@ -272,33 +261,28 @@ ExecEndSeqScan(SeqScan *node) { CommonScanState *scanstate; - /* ---------------- - * get information from node - * ---------------- + /* + * get information from node */ scanstate = node->scanstate; - /* ---------------- - * Free the projection info and the scan attribute info + /* + * Free the projection info and the scan attribute info * - * Note: we don't ExecFreeResultType(scanstate) - * because the rule manager depends on the tupType - * returned by ExecMain(). So for now, this - * is freed at end-transaction time. -cim 6/2/91 - * ---------------- + * Note: we don't ExecFreeResultType(scanstate) because the rule manager + * depends on the tupType returned by ExecMain(). So for now, this is + * freed at end-transaction time. -cim 6/2/91 */ ExecFreeProjectionInfo(&scanstate->cstate); ExecFreeExprContext(&scanstate->cstate); - /* ---------------- + /* * close scan relation - * ---------------- */ ExecCloseR((Plan *) node); - /* ---------------- - * clean out the tuple table - * ---------------- + /* + * clean out the tuple table */ ExecClearTuple(scanstate->cstate.cs_ResultTupleSlot); ExecClearTuple(scanstate->css_ScanTupleSlot); |