diff options
Diffstat (limited to 'src/backend/executor/nodeSeqscan.c')
| -rw-r--r-- | src/backend/executor/nodeSeqscan.c | 31 |
1 files changed, 11 insertions, 20 deletions
diff --git a/src/backend/executor/nodeSeqscan.c b/src/backend/executor/nodeSeqscan.c index c83aa725a7..eb73733b58 100644 --- a/src/backend/executor/nodeSeqscan.c +++ b/src/backend/executor/nodeSeqscan.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/executor/nodeSeqscan.c,v 1.20 1999/07/16 04:58:52 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/executor/nodeSeqscan.c,v 1.21 1999/09/24 00:24:24 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -74,20 +74,20 @@ SeqNext(SeqScan *node) if (estate->es_evTuple != NULL && estate->es_evTuple[node->scanrelid - 1] != NULL) { - slot->ttc_buffer = InvalidBuffer; - slot->ttc_shouldFree = false; + ExecClearTuple(slot); if (estate->es_evTupleNull[node->scanrelid - 1]) - { - slot->val = NULL; /* must not free tuple! */ - return (slot); - } + return slot; /* return empty slot */ + + /* probably ought to use ExecStoreTuple here... */ slot->val = estate->es_evTuple[node->scanrelid - 1]; + slot->ttc_shouldFree = false; /* * Note that unlike IndexScan, SeqScan never use keys in - * heap_beginscan (and this is very bad) - so, here we have not + * heap_beginscan (and this is very bad) - so, here we do not * check are keys ok or not. */ + /* Flag for the next call that no more tuples */ estate->es_evTupleNull[node->scanrelid - 1] = true; return (slot); @@ -104,7 +104,9 @@ SeqNext(SeqScan *node) * 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. + * 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. * ---------------- */ @@ -114,17 +116,6 @@ SeqNext(SeqScan *node) * this tuple */ false); /* don't pfree this pointer */ - /* ---------------- - * XXX -- mao says: The sequential scan for heap relations will - * automatically unpin the buffer this tuple is on when we cross - * a page boundary. The clearslot code also does this. We bump - * the pin count on the page here, since we actually have two - * pointers to it -- one in the scan desc and one in the tuple - * table slot. --mar 20 91 - * ---------------- - */ - ExecIncrSlotBufferRefcnt(slot); - return slot; } |