Tweak heap_update/delete so that we do not hold the buffer context lock
on the old tuple's page while we are doing TOAST pushups.
This commit is contained in:
Tom Lane
parent
0b5d194aaa
commit
efd6cade83
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@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.107 2001/01/12 21:53:54 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.108 2001/01/15 05:29:19 tgl Exp $
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*
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*
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* INTERFACE ROUTINES
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@ -1534,18 +1534,20 @@ l1:
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}
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END_CRIT_SECTION();
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LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
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#ifdef TUPLE_TOASTER_ACTIVE
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/* ----------
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* If the relation has toastable attributes, we need to delete
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* no longer needed items there too.
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* no longer needed items there too. We have to do this before
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* WriteBuffer because we need to look at the contents of the tuple,
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* but it's OK to release the context lock on the buffer first.
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* ----------
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*/
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if (HeapTupleHasExtended(&tp))
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heap_tuple_toast_attrs(relation, NULL, &(tp));
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#endif
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LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
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/*
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* Mark tuple for invalidation from system caches at next command boundary.
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* We have to do this before WriteBuffer because we need to look at the
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@ -1568,7 +1570,10 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
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ItemId lp;
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HeapTupleData oldtup;
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PageHeader dp;
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Buffer buffer, newbuf;
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Buffer buffer,
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newbuf;
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bool need_toast,
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already_marked;
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int result;
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/* increment access statistics */
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@ -1645,7 +1650,7 @@ l2:
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return result;
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}
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/* XXX order problems if not atomic assignment ??? */
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/* Fill in OID and transaction status data for newtup */
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newtup->t_data->t_oid = oldtup.t_data->t_oid;
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TransactionIdStore(GetCurrentTransactionId(), &(newtup->t_data->t_xmin));
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newtup->t_data->t_cmin = GetCurrentCommandId();
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@ -1653,70 +1658,85 @@ l2:
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newtup->t_data->t_infomask &= ~(HEAP_XACT_MASK);
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newtup->t_data->t_infomask |= (HEAP_XMAX_INVALID | HEAP_UPDATED);
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#ifdef TUPLE_TOASTER_ACTIVE
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/* ----------
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* If this relation is enabled for toasting, let the toaster
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* delete any no-longer-needed entries and create new ones to
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* make the new tuple fit again. Also, if there are already-
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* toasted values from some other relation, the toaster must
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* fix them.
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* ----------
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/*
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* If the toaster needs to be activated, OR if the new tuple will not
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* fit on the same page as the old, then we need to release the context
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* lock (but not the pin!) on the old tuple's buffer while we are off
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* doing TOAST and/or table-file-extension work. We must mark the old
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* tuple to show that it's already being updated, else other processes
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* may try to update it themselves. To avoid second XLOG log record,
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* we use xact mgr hook to unlock old tuple without reading log if xact
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* will abort before update is logged. In the event of crash prio logging,
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* TQUAL routines will see HEAP_XMAX_UNLOGGED flag...
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*
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* NOTE: this trick is useless currently but saved for future
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* when we'll implement UNDO and will re-use transaction IDs
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* after postmaster startup.
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*
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* We need to invoke the toaster if there are already any toasted values
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* present, or if the new tuple is over-threshold.
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*/
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if (HeapTupleHasExtended(&oldtup) ||
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HeapTupleHasExtended(newtup) ||
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(MAXALIGN(newtup->t_len) > TOAST_TUPLE_THRESHOLD))
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heap_tuple_toast_attrs(relation, newtup, &oldtup);
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#endif
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need_toast = (HeapTupleHasExtended(&oldtup) ||
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HeapTupleHasExtended(newtup) ||
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(MAXALIGN(newtup->t_len) > TOAST_TUPLE_THRESHOLD));
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/* Find buffer for new tuple */
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if ((unsigned) MAXALIGN(newtup->t_len) <= PageGetFreeSpace((Page) dp))
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newbuf = buffer;
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else
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if (need_toast ||
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(unsigned) MAXALIGN(newtup->t_len) > PageGetFreeSpace((Page) dp))
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{
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/*
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* We have to unlock old tuple buffer before extending table
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* file but have to keep lock on the old tuple. To avoid second
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* XLOG log record we use xact mngr hook to unlock old tuple
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* without reading log if xact will abort before update is logged.
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* In the event of crash prio logging, TQUAL routines will see
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* HEAP_XMAX_UNLOGGED flag...
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*
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* NOTE: this trick is useless currently but saved for future
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* when we'll implement UNDO and will re-use transaction IDs
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* after postmaster startup.
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*/
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_locked_tuple_.node = relation->rd_node;
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_locked_tuple_.tid = oldtup.t_self;
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XactPushRollback(_heap_unlock_tuple, (void*) &_locked_tuple_);
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TransactionIdStore(GetCurrentTransactionId(), &(oldtup.t_data->t_xmax));
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TransactionIdStore(GetCurrentTransactionId(),
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&(oldtup.t_data->t_xmax));
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oldtup.t_data->t_cmax = GetCurrentCommandId();
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oldtup.t_data->t_infomask &= ~(HEAP_XMAX_COMMITTED |
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HEAP_XMAX_INVALID | HEAP_MARKED_FOR_UPDATE);
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HEAP_XMAX_INVALID |
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HEAP_MARKED_FOR_UPDATE);
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oldtup.t_data->t_infomask |= HEAP_XMAX_UNLOGGED;
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already_marked = true;
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LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
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newbuf = RelationGetBufferForTuple(relation, newtup->t_len);
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/* Let the toaster do its thing */
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if (need_toast)
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heap_tuple_toast_attrs(relation, newtup, &oldtup);
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/* Now, do we need a new page for the tuple, or not? */
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if ((unsigned) MAXALIGN(newtup->t_len) <= PageGetFreeSpace((Page) dp))
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newbuf = buffer;
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else
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newbuf = RelationGetBufferForTuple(relation, newtup->t_len);
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/* Re-acquire the lock on the old tuple's page. */
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/* this seems to be deadlock free... */
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LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
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}
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else
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{
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/* No TOAST work needed, and it'll fit on same page */
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already_marked = false;
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newbuf = buffer;
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}
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/* NO ELOG(ERROR) from here till changes are logged */
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START_CRIT_SECTION();
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RelationPutHeapTuple(relation, newbuf, newtup); /* insert new tuple */
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if (buffer == newbuf)
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{
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TransactionIdStore(GetCurrentTransactionId(), &(oldtup.t_data->t_xmax));
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oldtup.t_data->t_cmax = GetCurrentCommandId();
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oldtup.t_data->t_infomask &= ~(HEAP_XMAX_COMMITTED |
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HEAP_XMAX_INVALID | HEAP_MARKED_FOR_UPDATE);
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}
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else
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if (already_marked)
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{
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oldtup.t_data->t_infomask &= ~HEAP_XMAX_UNLOGGED;
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XactPopRollback();
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}
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else
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{
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TransactionIdStore(GetCurrentTransactionId(),
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&(oldtup.t_data->t_xmax));
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oldtup.t_data->t_cmax = GetCurrentCommandId();
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oldtup.t_data->t_infomask &= ~(HEAP_XMAX_COMMITTED |
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HEAP_XMAX_INVALID |
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HEAP_MARKED_FOR_UPDATE);
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}
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/* record address of new tuple in t_ctid of old one */
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oldtup.t_data->t_ctid = newtup->t_self;
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@ -1724,7 +1744,7 @@ l2:
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/* XLOG stuff */
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{
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XLogRecPtr recptr = log_heap_update(relation, buffer, oldtup.t_self,
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newbuf, newtup, false);
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newbuf, newtup, false);
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if (newbuf != buffer)
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{
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@ -1734,6 +1754,7 @@ l2:
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PageSetLSN(BufferGetPage(buffer), recptr);
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PageSetSUI(BufferGetPage(buffer), ThisStartUpID);
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}
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END_CRIT_SECTION();
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if (newbuf != buffer)
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@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/access/heap/tuptoaster.c,v 1.13 2000/10/23 23:42:04 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/access/heap/tuptoaster.c,v 1.14 2001/01/15 05:29:19 tgl Exp $
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*
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*
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* INTERFACE ROUTINES
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@ -197,10 +197,12 @@ toast_delete(Relation rel, HeapTuple oldtup)
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*/
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for (i = 0; i < numAttrs; i++)
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{
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value = heap_getattr(oldtup, i + 1, tupleDesc, &isnull);
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if (!isnull && att[i]->attlen == -1)
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if (VARATT_IS_EXTERNAL(value))
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if (att[i]->attlen == -1)
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{
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value = heap_getattr(oldtup, i + 1, tupleDesc, &isnull);
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if (!isnull && VARATT_IS_EXTERNAL(value))
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toast_delete_datum(rel, value);
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}
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}
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}
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