diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index db443218b4..c8436b709d 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.107 2001/01/12 21:53:54 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/heap/heapam.c,v 1.108 2001/01/15 05:29:19 tgl Exp $
*
*
* INTERFACE ROUTINES
@@ -1534,18 +1534,20 @@ l1:
}
END_CRIT_SECTION();
+ LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
+
#ifdef TUPLE_TOASTER_ACTIVE
/* ----------
* If the relation has toastable attributes, we need to delete
- * no longer needed items there too.
+ * no longer needed items there too. We have to do this before
+ * WriteBuffer because we need to look at the contents of the tuple,
+ * but it's OK to release the context lock on the buffer first.
* ----------
*/
if (HeapTupleHasExtended(&tp))
heap_tuple_toast_attrs(relation, NULL, &(tp));
#endif
- LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
-
/*
* Mark tuple for invalidation from system caches at next command boundary.
* We have to do this before WriteBuffer because we need to look at the
@@ -1568,7 +1570,10 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
ItemId lp;
HeapTupleData oldtup;
PageHeader dp;
- Buffer buffer, newbuf;
+ Buffer buffer,
+ newbuf;
+ bool need_toast,
+ already_marked;
int result;
/* increment access statistics */
@@ -1645,7 +1650,7 @@ l2:
return result;
}
- /* XXX order problems if not atomic assignment ??? */
+ /* Fill in OID and transaction status data for newtup */
newtup->t_data->t_oid = oldtup.t_data->t_oid;
TransactionIdStore(GetCurrentTransactionId(), &(newtup->t_data->t_xmin));
newtup->t_data->t_cmin = GetCurrentCommandId();
@@ -1653,70 +1658,85 @@ l2:
newtup->t_data->t_infomask &= ~(HEAP_XACT_MASK);
newtup->t_data->t_infomask |= (HEAP_XMAX_INVALID | HEAP_UPDATED);
-#ifdef TUPLE_TOASTER_ACTIVE
- /* ----------
- * If this relation is enabled for toasting, let the toaster
- * delete any no-longer-needed entries and create new ones to
- * make the new tuple fit again. Also, if there are already-
- * toasted values from some other relation, the toaster must
- * fix them.
- * ----------
+ /*
+ * If the toaster needs to be activated, OR if the new tuple will not
+ * fit on the same page as the old, then we need to release the context
+ * lock (but not the pin!) on the old tuple's buffer while we are off
+ * doing TOAST and/or table-file-extension work. We must mark the old
+ * tuple to show that it's already being updated, else other processes
+ * may try to update it themselves. To avoid second XLOG log record,
+ * we use xact mgr hook to unlock old tuple without reading log if xact
+ * will abort before update is logged. In the event of crash prio logging,
+ * TQUAL routines will see HEAP_XMAX_UNLOGGED flag...
+ *
+ * NOTE: this trick is useless currently but saved for future
+ * when we'll implement UNDO and will re-use transaction IDs
+ * after postmaster startup.
+ *
+ * We need to invoke the toaster if there are already any toasted values
+ * present, or if the new tuple is over-threshold.
*/
- if (HeapTupleHasExtended(&oldtup) ||
- HeapTupleHasExtended(newtup) ||
- (MAXALIGN(newtup->t_len) > TOAST_TUPLE_THRESHOLD))
- heap_tuple_toast_attrs(relation, newtup, &oldtup);
-#endif
+ need_toast = (HeapTupleHasExtended(&oldtup) ||
+ HeapTupleHasExtended(newtup) ||
+ (MAXALIGN(newtup->t_len) > TOAST_TUPLE_THRESHOLD));
- /* Find buffer for new tuple */
-
- if ((unsigned) MAXALIGN(newtup->t_len) <= PageGetFreeSpace((Page) dp))
- newbuf = buffer;
- else
+ if (need_toast ||
+ (unsigned) MAXALIGN(newtup->t_len) > PageGetFreeSpace((Page) dp))
{
- /*
- * We have to unlock old tuple buffer before extending table
- * file but have to keep lock on the old tuple. To avoid second
- * XLOG log record we use xact mngr hook to unlock old tuple
- * without reading log if xact will abort before update is logged.
- * In the event of crash prio logging, TQUAL routines will see
- * HEAP_XMAX_UNLOGGED flag...
- *
- * NOTE: this trick is useless currently but saved for future
- * when we'll implement UNDO and will re-use transaction IDs
- * after postmaster startup.
- */
_locked_tuple_.node = relation->rd_node;
_locked_tuple_.tid = oldtup.t_self;
XactPushRollback(_heap_unlock_tuple, (void*) &_locked_tuple_);
- TransactionIdStore(GetCurrentTransactionId(), &(oldtup.t_data->t_xmax));
+ TransactionIdStore(GetCurrentTransactionId(),
+ &(oldtup.t_data->t_xmax));
oldtup.t_data->t_cmax = GetCurrentCommandId();
oldtup.t_data->t_infomask &= ~(HEAP_XMAX_COMMITTED |
- HEAP_XMAX_INVALID | HEAP_MARKED_FOR_UPDATE);
+ HEAP_XMAX_INVALID |
+ HEAP_MARKED_FOR_UPDATE);
oldtup.t_data->t_infomask |= HEAP_XMAX_UNLOGGED;
+ already_marked = true;
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
- newbuf = RelationGetBufferForTuple(relation, newtup->t_len);
+
+ /* Let the toaster do its thing */
+ if (need_toast)
+ heap_tuple_toast_attrs(relation, newtup, &oldtup);
+
+ /* Now, do we need a new page for the tuple, or not? */
+ if ((unsigned) MAXALIGN(newtup->t_len) <= PageGetFreeSpace((Page) dp))
+ newbuf = buffer;
+ else
+ newbuf = RelationGetBufferForTuple(relation, newtup->t_len);
+
+ /* Re-acquire the lock on the old tuple's page. */
/* this seems to be deadlock free... */
LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
}
+ else
+ {
+ /* No TOAST work needed, and it'll fit on same page */
+ already_marked = false;
+ newbuf = buffer;
+ }
/* NO ELOG(ERROR) from here till changes are logged */
START_CRIT_SECTION();
RelationPutHeapTuple(relation, newbuf, newtup); /* insert new tuple */
- if (buffer == newbuf)
- {
- TransactionIdStore(GetCurrentTransactionId(), &(oldtup.t_data->t_xmax));
- oldtup.t_data->t_cmax = GetCurrentCommandId();
- oldtup.t_data->t_infomask &= ~(HEAP_XMAX_COMMITTED |
- HEAP_XMAX_INVALID | HEAP_MARKED_FOR_UPDATE);
- }
- else
+
+ if (already_marked)
{
oldtup.t_data->t_infomask &= ~HEAP_XMAX_UNLOGGED;
XactPopRollback();
}
+ else
+ {
+ TransactionIdStore(GetCurrentTransactionId(),
+ &(oldtup.t_data->t_xmax));
+ oldtup.t_data->t_cmax = GetCurrentCommandId();
+ oldtup.t_data->t_infomask &= ~(HEAP_XMAX_COMMITTED |
+ HEAP_XMAX_INVALID |
+ HEAP_MARKED_FOR_UPDATE);
+ }
/* record address of new tuple in t_ctid of old one */
oldtup.t_data->t_ctid = newtup->t_self;
@@ -1724,7 +1744,7 @@ l2:
/* XLOG stuff */
{
XLogRecPtr recptr = log_heap_update(relation, buffer, oldtup.t_self,
- newbuf, newtup, false);
+ newbuf, newtup, false);
if (newbuf != buffer)
{
@@ -1734,6 +1754,7 @@ l2:
PageSetLSN(BufferGetPage(buffer), recptr);
PageSetSUI(BufferGetPage(buffer), ThisStartUpID);
}
+
END_CRIT_SECTION();
if (newbuf != buffer)
diff --git a/src/backend/access/heap/tuptoaster.c b/src/backend/access/heap/tuptoaster.c
index 2787611dd0..46495404b8 100644
--- a/src/backend/access/heap/tuptoaster.c
+++ b/src/backend/access/heap/tuptoaster.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/access/heap/tuptoaster.c,v 1.13 2000/10/23 23:42:04 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/heap/tuptoaster.c,v 1.14 2001/01/15 05:29:19 tgl Exp $
*
*
* INTERFACE ROUTINES
@@ -197,10 +197,12 @@ toast_delete(Relation rel, HeapTuple oldtup)
*/
for (i = 0; i < numAttrs; i++)
{
- value = heap_getattr(oldtup, i + 1, tupleDesc, &isnull);
- if (!isnull && att[i]->attlen == -1)
- if (VARATT_IS_EXTERNAL(value))
+ if (att[i]->attlen == -1)
+ {
+ value = heap_getattr(oldtup, i + 1, tupleDesc, &isnull);
+ if (!isnull && VARATT_IS_EXTERNAL(value))
toast_delete_datum(rel, value);
+ }
}
}