diff options
Diffstat (limited to 'src/backend/access/nbtree/nbtinsert.c')
| -rw-r--r-- | src/backend/access/nbtree/nbtinsert.c | 108 |
1 files changed, 61 insertions, 47 deletions
diff --git a/src/backend/access/nbtree/nbtinsert.c b/src/backend/access/nbtree/nbtinsert.c index 3a94297188c..fe3e98b982c 100644 --- a/src/backend/access/nbtree/nbtinsert.c +++ b/src/backend/access/nbtree/nbtinsert.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.90 2002/03/06 06:09:17 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.91 2002/05/24 18:57:55 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -176,7 +176,6 @@ _bt_check_unique(Relation rel, BTItem btitem, Relation heapRel, Page page; BTPageOpaque opaque; Buffer nbuf = InvalidBuffer; - bool chtup = true; page = BufferGetPage(buf); opaque = (BTPageOpaque) PageGetSpecialPointer(page); @@ -194,70 +193,85 @@ _bt_check_unique(Relation rel, BTItem btitem, Relation heapRel, for (;;) { HeapTupleData htup; - Buffer buffer; + Buffer hbuffer; + ItemId curitemid; BTItem cbti; BlockNumber nblkno; /* - * _bt_compare returns 0 for (1,NULL) and (1,NULL) - this's how we - * handling NULLs - and so we must not use _bt_compare in real - * comparison, but only for ordering/finding items on pages. - - * vadim 03/24/97 - * * make sure the offset points to an actual key before trying to * compare it... */ if (offset <= maxoff) { + /* + * _bt_compare returns 0 for (1,NULL) and (1,NULL) - this's how we + * handling NULLs - and so we must not use _bt_compare in real + * comparison, but only for ordering/finding items on pages. - + * vadim 03/24/97 + */ if (!_bt_isequal(itupdesc, page, offset, natts, itup_scankey)) break; /* we're past all the equal tuples */ + curitemid = PageGetItemId(page, offset); /* - * Have to check is inserted heap tuple deleted one (i.e. just - * moved to another place by vacuum)! We only need to do this - * once, but don't want to do it at all unless we see equal - * tuples, so as not to slow down unequal case. + * We can skip the heap fetch if the item is marked killed. */ - if (chtup) - { - htup.t_self = btitem->bti_itup.t_tid; - heap_fetch(heapRel, SnapshotDirty, &htup, &buffer, NULL); - if (htup.t_data == NULL) /* YES! */ - break; - /* Live tuple is being inserted, so continue checking */ - ReleaseBuffer(buffer); - chtup = false; - } - - cbti = (BTItem) PageGetItem(page, PageGetItemId(page, offset)); - htup.t_self = cbti->bti_itup.t_tid; - heap_fetch(heapRel, SnapshotDirty, &htup, &buffer, NULL); - if (htup.t_data != NULL) /* it is a duplicate */ + if (!ItemIdDeleted(curitemid)) { - TransactionId xwait = - (TransactionIdIsValid(SnapshotDirty->xmin)) ? - SnapshotDirty->xmin : SnapshotDirty->xmax; + cbti = (BTItem) PageGetItem(page, curitemid); + htup.t_self = cbti->bti_itup.t_tid; + if (heap_fetch(heapRel, SnapshotDirty, &htup, &hbuffer, + true, NULL)) + { + /* it is a duplicate */ + TransactionId xwait = + (TransactionIdIsValid(SnapshotDirty->xmin)) ? + SnapshotDirty->xmin : SnapshotDirty->xmax; + + ReleaseBuffer(hbuffer); + /* + * If this tuple is being updated by other transaction + * then we have to wait for its commit/abort. + */ + if (TransactionIdIsValid(xwait)) + { + if (nbuf != InvalidBuffer) + _bt_relbuf(rel, nbuf); + /* Tell _bt_doinsert to wait... */ + return xwait; + } - /* - * If this tuple is being updated by other transaction - * then we have to wait for its commit/abort. - */ - ReleaseBuffer(buffer); - if (TransactionIdIsValid(xwait)) + /* + * Otherwise we have a definite conflict. + */ + elog(ERROR, "Cannot insert a duplicate key into unique index %s", + RelationGetRelationName(rel)); + } + else { - if (nbuf != InvalidBuffer) - _bt_relbuf(rel, nbuf); - /* Tell _bt_doinsert to wait... */ - return xwait; + /* + * Hmm, if we can't see the tuple, maybe it can be + * marked killed. This logic should match index_getnext + * and btgettuple. + */ + uint16 sv_infomask; + + LockBuffer(hbuffer, BUFFER_LOCK_SHARE); + sv_infomask = htup.t_data->t_infomask; + if (HeapTupleSatisfiesVacuum(htup.t_data, + RecentGlobalXmin) == + HEAPTUPLE_DEAD) + { + curitemid->lp_flags |= LP_DELETE; + SetBufferCommitInfoNeedsSave(buf); + } + if (sv_infomask != htup.t_data->t_infomask) + SetBufferCommitInfoNeedsSave(hbuffer); + LockBuffer(hbuffer, BUFFER_LOCK_UNLOCK); + ReleaseBuffer(hbuffer); } - - /* - * Otherwise we have a definite conflict. - */ - elog(ERROR, "Cannot insert a duplicate key into unique index %s", - RelationGetRelationName(rel)); } - /* htup null so no buffer to release */ } /* |