opensourcemirror
/
postgresql
mirror of git://git.postgresql.org/git/postgresql.git
1
0
Fork 0
Code Issues Releases Wiki Activity

_bt_updateitem is returned in code, but works only if sizes of keys 

are equal.
This commit is contained in:
Vadim B. Mikheev 1996-12-06 09:45:30 +00:00
parent c3e10a4caf
commit 4e064c0560
1 changed files with 76 additions and 50 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

126
src/backend/access/nbtree/nbtinsert.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.7 1996/11/13 20:47:11 scrappy Exp $
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.8 1996/12/06 09:45:30 vadim Exp $
*
*-------------------------------------------------------------------------
*/
@ -31,10 +31,7 @@ static OffsetNumber _bt_findsplitloc(Relation rel, Page page, OffsetNumber start
static void _bt_newroot(Relation rel, Buffer lbuf, Buffer rbuf);
static OffsetNumber _bt_pgaddtup(Relation rel, Buffer buf, int keysz, ScanKey itup_scankey, Size itemsize, BTItem btitem, BTItem afteritem);
static bool _bt_goesonpg(Relation rel, Buffer buf, Size keysz, ScanKey scankey, BTItem afteritem);
#if 0
static void _bt_updateitem(Relation rel, Size keysz, Buffer buf, Oid bti_oid, BTItem newItem);
#endif
/*
* _bt_doinsert() -- Handle insertion of a single btitem in the tree.
@ -265,6 +262,8 @@ _bt_insertonpg(Relation rel,
if (_bt_itemcmp(rel, keysz, stack->bts_btitem, new_item,
BTGreaterStrategyNumber)) {
ppageop = (BTPageOpaque) PageGetSpecialPointer(page);
Assert (P_LEFTMOST(ppageop));
lowLeftItem =
(BTItem) PageGetItem(page,
PageGetItemId(page, P_FIRSTKEY));
@ -278,56 +277,80 @@ _bt_insertonpg(Relation rel,
/* because it's bigger than what was there before). */
/* --djm 8/21/96 */
/* _bt_updateitem(rel, keysz, pbuf, stack->bts_btitem->bti_oid,
lowLeftItem); */
/* get the parent page */
ppage = BufferGetPage(pbuf);
ppageop = (BTPageOpaque) PageGetSpecialPointer(ppage);
/*
* but it works for items with the same size and so why don't
* use it for them ? - vadim 12/05/96
*/
if ( DOUBLEALIGN (IndexTupleDSize (lowLeftItem->bti_itup)) ==
DOUBLEALIGN (IndexTupleDSize (stack->bts_btitem->bti_itup)) )
{
_bt_updateitem(rel, keysz, pbuf,
stack->bts_btitem->bti_oid, lowLeftItem);
_bt_relbuf(rel, buf, BT_WRITE);
_bt_relbuf(rel, rbuf, BT_WRITE);
}
else
{
/* get the parent page */
ppage = BufferGetPage(pbuf);
ppageop = (BTPageOpaque) PageGetSpecialPointer(ppage);
/* figure out which key is leftmost (if the parent page */
/* is rightmost, too, it must be the root) */
if(P_RIGHTMOST(ppageop)) {
leftmost_offset = P_HIKEY;
} else {
leftmost_offset = P_FIRSTKEY;
}
PageIndexTupleDelete(ppage, leftmost_offset);
/*
* figure out which key is leftmost (if the parent page
* is rightmost, too, it must be the root)
*/
if(P_RIGHTMOST(ppageop)) {
leftmost_offset = P_HIKEY;
} else {
leftmost_offset = P_FIRSTKEY;
}
PageIndexTupleDelete(ppage, leftmost_offset);
/* don't write anything out yet--we still have the write */
/* lock, and now we call another _bt_insertonpg to */
/* insert the correct leftmost key */
/*
* don't write anything out yet--we still have the write
* lock, and now we call another _bt_insertonpg to
* insert the correct leftmost key
*/
/* make a new leftmost item, using the tuple data from */
/* lowLeftItem. point it to the left child. */
/* update it on the stack at the same time. */
bknum = BufferGetBlockNumber(buf);
pfree(stack->bts_btitem);
stack->bts_btitem = _bt_formitem(&(lowLeftItem->bti_itup));
ItemPointerSet(&(stack->bts_btitem->bti_itup.t_tid),
/*
* make a new leftmost item, using the tuple data from
* lowLeftItem. point it to the left child.
* update it on the stack at the same time.
*/
bknum = BufferGetBlockNumber(buf);
pfree(stack->bts_btitem);
stack->bts_btitem = _bt_formitem(&(lowLeftItem->bti_itup));
ItemPointerSet(&(stack->bts_btitem->bti_itup.t_tid),
bknum, P_HIKEY);
/* unlock the children before doing this */
_bt_relbuf(rel, buf, BT_WRITE);
_bt_relbuf(rel, rbuf, BT_WRITE);
/* unlock the children before doing this */
_bt_relbuf(rel, buf, BT_WRITE);
_bt_relbuf(rel, rbuf, BT_WRITE);
/* a regular _bt_binsrch should find the right place to */
/* put the new entry, since it should be lower than any */
/* other key on the page, therefore set afteritem to NULL */
newskey = _bt_mkscankey(rel, &(stack->bts_btitem->bti_itup));
newres = _bt_insertonpg(rel, pbuf, stack->bts_parent,
/*
* a regular _bt_binsrch should find the right place to
* put the new entry, since it should be lower than any
* other key on the page, therefore set afteritem to NULL
*/
newskey = _bt_mkscankey(rel, &(stack->bts_btitem->bti_itup));
newres = _bt_insertonpg(rel, pbuf, stack->bts_parent,
keysz, newskey, stack->bts_btitem,
NULL);
pfree(newres);
pfree(newskey);
pfree(newres);
pfree(newskey);
/* we have now lost our lock on the parent buffer, and */
/* need to get it back. */
pbuf = _bt_getstackbuf(rel, stack, BT_WRITE);
} else {
_bt_relbuf(rel, buf, BT_WRITE);
_bt_relbuf(rel, rbuf, BT_WRITE);
/*
* we have now lost our lock on the parent buffer, and
* need to get it back.
*/
pbuf = _bt_getstackbuf(rel, stack, BT_WRITE);
}
}
else
{
_bt_relbuf(rel, buf, BT_WRITE);
_bt_relbuf(rel, rbuf, BT_WRITE);
}
newskey = _bt_mkscankey(rel, &(new_item->bti_itup));
@ -872,8 +895,6 @@ _bt_itemcmp(Relation rel,
return (true);
}
#if 0
/* gone since updating in place doesn't work in general --djm 11/13/96 */
/*
* _bt_updateitem() -- updates the key of the item identified by the
* oid with the key of newItem (done in place if
@ -912,18 +933,23 @@ _bt_updateitem(Relation rel,
elog(FATAL, "_bt_getstackbuf was lying!!");
}
/*
* It's defined by caller (_bt_insertonpg)
*/
/*
if(IndexTupleDSize(newItem->bti_itup) >
IndexTupleDSize(item->bti_itup)) {
elog(NOTICE, "trying to overwrite a smaller value with a bigger one in _bt_updateitem");
elog(WARN, "this is not good.");
}
*/
oldIndexTuple = &(item->bti_itup);
newIndexTuple = &(newItem->bti_itup);
/* keep the original item pointer */
ItemPointerCopy(&(oldIndexTuple->t_tid), &itemPtrData);
CopyIndexTuple(newIndexTuple, &oldIndexTuple);
ItemPointerCopy(&itemPtrData, &(oldIndexTuple->t_tid));
ItemPointerCopy(&(oldIndexTuple->t_tid), &itemPtrData);
CopyIndexTuple(newIndexTuple, &oldIndexTuple);
ItemPointerCopy(&itemPtrData, &(oldIndexTuple->t_tid));
}
#endif