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path: root/src/backend/access/nbtree/nbtinsert.c
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Diffstat (limited to 'src/backend/access/nbtree/nbtinsert.c')
-rw-r--r--src/backend/access/nbtree/nbtinsert.c161
1 files changed, 97 insertions, 64 deletions
diff --git a/src/backend/access/nbtree/nbtinsert.c b/src/backend/access/nbtree/nbtinsert.c
index a93a9fed8c6..e943ca96f1b 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 1.97 2003/02/21 00:06:21 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.98 2003/02/22 00:45:03 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -280,12 +280,21 @@ _bt_check_unique(Relation rel, BTItem btitem, Relation heapRel,
if (!_bt_isequal(itupdesc, page, P_HIKEY,
natts, itup_scankey))
break;
- nblkno = opaque->btpo_next;
- if (nbuf != InvalidBuffer)
- _bt_relbuf(rel, nbuf);
- nbuf = _bt_getbuf(rel, nblkno, BT_READ);
- page = BufferGetPage(nbuf);
- opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+ /* Advance to next non-dead page --- there must be one */
+ for (;;)
+ {
+ nblkno = opaque->btpo_next;
+ if (nbuf != InvalidBuffer)
+ _bt_relbuf(rel, nbuf);
+ nbuf = _bt_getbuf(rel, nblkno, BT_READ);
+ page = BufferGetPage(nbuf);
+ opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+ if (!P_IGNORE(opaque))
+ break;
+ if (P_RIGHTMOST(opaque))
+ elog(ERROR, "_bt_check_unique: fell off the end of %s",
+ RelationGetRelationName(rel));
+ }
maxoff = PageGetMaxOffsetNumber(page);
offset = P_FIRSTDATAKEY(opaque);
}
@@ -414,20 +423,34 @@ _bt_insertonpg(Relation rel,
_bt_compare(rel, keysz, scankey, page, P_HIKEY) == 0 &&
random() > (MAX_RANDOM_VALUE / 100))
{
- /* step right one page */
- BlockNumber rblkno = lpageop->btpo_next;
- Buffer rbuf;
-
/*
- * must write-lock next page before releasing write lock on
+ * step right to next non-dead page
+ *
+ * must write-lock that page before releasing write lock on
* current page; else someone else's _bt_check_unique scan
- * could fail to see our insertion.
+ * could fail to see our insertion. write locks on intermediate
+ * dead pages won't do because we don't know when they will get
+ * de-linked from the tree.
*/
- rbuf = _bt_getbuf(rel, rblkno, BT_WRITE);
+ Buffer rbuf = InvalidBuffer;
+
+ for (;;)
+ {
+ BlockNumber rblkno = lpageop->btpo_next;
+
+ if (rbuf != InvalidBuffer)
+ _bt_relbuf(rel, rbuf);
+ rbuf = _bt_getbuf(rel, rblkno, BT_WRITE);
+ page = BufferGetPage(rbuf);
+ lpageop = (BTPageOpaque) PageGetSpecialPointer(page);
+ if (!P_IGNORE(lpageop))
+ break;
+ if (P_RIGHTMOST(lpageop))
+ elog(ERROR, "_bt_insertonpg: fell off the end of %s",
+ RelationGetRelationName(rel));
+ }
_bt_relbuf(rel, buf);
buf = rbuf;
- page = BufferGetPage(buf);
- lpageop = (BTPageOpaque) PageGetSpecialPointer(page);
movedright = true;
}
@@ -633,8 +656,9 @@ _bt_split(Relation rel, Buffer buf, OffsetNumber firstright,
BTPageOpaque ropaque,
lopaque,
oopaque;
- Buffer sbuf = 0;
- Page spage = 0;
+ Buffer sbuf = InvalidBuffer;
+ Page spage = NULL;
+ BTPageOpaque sopaque = NULL;
Size itemsz;
ItemId itemid;
BTItem item;
@@ -792,6 +816,9 @@ _bt_split(Relation rel, Buffer buf, OffsetNumber firstright,
{
sbuf = _bt_getbuf(rel, ropaque->btpo_next, BT_WRITE);
spage = BufferGetPage(sbuf);
+ sopaque = (BTPageOpaque) PageGetSpecialPointer(spage);
+ if (sopaque->btpo_prev != ropaque->btpo_prev)
+ elog(PANIC, "btree: right sibling's left-link doesn't match");
}
/*
@@ -802,6 +829,9 @@ _bt_split(Relation rel, Buffer buf, OffsetNumber firstright,
*/
START_CRIT_SECTION();
+ if (!P_RIGHTMOST(ropaque))
+ sopaque->btpo_prev = BufferGetBlockNumber(rbuf);
+
/* XLOG stuff */
if (!rel->rd_istemp)
{
@@ -847,10 +877,6 @@ _bt_split(Relation rel, Buffer buf, OffsetNumber firstright,
if (!P_RIGHTMOST(ropaque))
{
- BTPageOpaque sopaque = (BTPageOpaque) PageGetSpecialPointer(spage);
-
- sopaque->btpo_prev = BufferGetBlockNumber(rbuf);
-
rdata[2].next = &(rdata[3]);
rdata[3].buffer = sbuf;
rdata[3].data = NULL;
@@ -1250,58 +1276,63 @@ _bt_getstackbuf(Relation rel, BTStack stack, int access)
Buffer buf;
Page page;
BTPageOpaque opaque;
- OffsetNumber offnum,
- minoff,
- maxoff;
- ItemId itemid;
- BTItem item;
buf = _bt_getbuf(rel, blkno, access);
page = BufferGetPage(buf);
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
- minoff = P_FIRSTDATAKEY(opaque);
- maxoff = PageGetMaxOffsetNumber(page);
- /*
- * start = InvalidOffsetNumber means "search the whole page".
- * We need this test anyway due to possibility that
- * page has a high key now when it didn't before.
- */
- if (start < minoff)
- start = minoff;
-
- /*
- * These loops will check every item on the page --- but in an order
- * that's attuned to the probability of where it actually is. Scan
- * to the right first, then to the left.
- */
- for (offnum = start;
- offnum <= maxoff;
- offnum = OffsetNumberNext(offnum))
+ if (!P_IGNORE(opaque))
{
- itemid = PageGetItemId(page, offnum);
- item = (BTItem) PageGetItem(page, itemid);
- if (BTItemSame(item, &stack->bts_btitem))
+ OffsetNumber offnum,
+ minoff,
+ maxoff;
+ ItemId itemid;
+ BTItem item;
+
+ minoff = P_FIRSTDATAKEY(opaque);
+ maxoff = PageGetMaxOffsetNumber(page);
+
+ /*
+ * start = InvalidOffsetNumber means "search the whole page".
+ * We need this test anyway due to possibility that
+ * page has a high key now when it didn't before.
+ */
+ if (start < minoff)
+ start = minoff;
+
+ /*
+ * These loops will check every item on the page --- but in an
+ * order that's attuned to the probability of where it actually
+ * is. Scan to the right first, then to the left.
+ */
+ for (offnum = start;
+ offnum <= maxoff;
+ offnum = OffsetNumberNext(offnum))
{
- /* Return accurate pointer to where link is now */
- stack->bts_blkno = blkno;
- stack->bts_offset = offnum;
- return buf;
+ itemid = PageGetItemId(page, offnum);
+ item = (BTItem) PageGetItem(page, itemid);
+ if (BTItemSame(item, &stack->bts_btitem))
+ {
+ /* Return accurate pointer to where link is now */
+ stack->bts_blkno = blkno;
+ stack->bts_offset = offnum;
+ return buf;
+ }
}
- }
- for (offnum = OffsetNumberPrev(start);
- offnum >= minoff;
- offnum = OffsetNumberPrev(offnum))
- {
- itemid = PageGetItemId(page, offnum);
- item = (BTItem) PageGetItem(page, itemid);
- if (BTItemSame(item, &stack->bts_btitem))
+ for (offnum = OffsetNumberPrev(start);
+ offnum >= minoff;
+ offnum = OffsetNumberPrev(offnum))
{
- /* Return accurate pointer to where link is now */
- stack->bts_blkno = blkno;
- stack->bts_offset = offnum;
- return buf;
+ itemid = PageGetItemId(page, offnum);
+ item = (BTItem) PageGetItem(page, itemid);
+ if (BTItemSame(item, &stack->bts_btitem))
+ {
+ /* Return accurate pointer to where link is now */
+ stack->bts_blkno = blkno;
+ stack->bts_offset = offnum;
+ return buf;
+ }
}
}
@@ -1365,6 +1396,8 @@ _bt_newroot(Relation rel, Buffer lbuf, Buffer rbuf)
rootbuf = _bt_getbuf(rel, P_NEW, BT_WRITE);
rootpage = BufferGetPage(rootbuf);
rootblknum = BufferGetBlockNumber(rootbuf);
+
+ /* acquire lock on the metapage */
metabuf = _bt_getbuf(rel, BTREE_METAPAGE, BT_WRITE);
metapg = BufferGetPage(metabuf);
metad = BTPageGetMeta(metapg);
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-22 22:17:15 +0000