database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-01 21:31:19 +03:00
Code Activity

More infrastructure for btree compaction project. Tree-traversal code

Browse Source 
now knows what to do upon hitting a dead page (in theory anyway, it's
untested...).  Add a post-VACUUM-cleanup entry point for index AMs, to
provide a place for dead-page scavenging to happen.
Also, fix oversight that broke btpo_prev links in temporary indexes.
initdb forced due to additions in pg_am.
This commit is contained in:
Tom Lane
2003-02-22 00:45:05 +00:00
parent 4fff132d1b
commit 799bc58dc7
18 changed files with 709 additions and 345 deletions
Download Patch File Download Diff File Expand all files Collapse all files

161
src/backend/access/nbtree/nbtinsert.c
View File

@@ -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);