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If we have to split leaf page in the chain of duplicates

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then we try to look at our right sibling first, but not farther,
as it was in yesterday fix.
This commit is contained in:
Vadim B. Mikheev 1997-05-31 06:35:56 +00:00
parent 5cf55737a4
commit 139858e699
1 changed files with 24 additions and 41 deletions
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65
src/backend/access/nbtree/nbtinsert.c
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@ -7,7 +7,7 @@
* *
* *
* IDENTIFICATION * IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.13 1997/05/30 18:35:31 vadim Exp $ * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.14 1997/05/31 06:35:56 vadim Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -287,31 +287,22 @@ _bt_insertonpg(Relation rel,
/* /*
* If we have to split leaf page in the chain of duplicates * If we have to split leaf page in the chain of duplicates
* then we try to move righter to avoid splitting. * then we try to look at our right sibling first.
*/ */
if ( ( lpageop->btpo_flags & BTP_CHAIN ) && if ( ( lpageop->btpo_flags & BTP_CHAIN ) &&
( lpageop->btpo_flags & BTP_LEAF ) ) ( lpageop->btpo_flags & BTP_LEAF ) )
{ {
bool use_left = true; bool use_left = true;
bool keys_equal = false;
for ( ; ; ) rbuf = _bt_getbuf(rel, lpageop->btpo_next, BT_WRITE);
{ rpage = BufferGetPage(rbuf);
bool keys_equal = false; rpageop = (BTPageOpaque) PageGetSpecialPointer(rpage);
if ( !P_RIGHTMOST (rpageop) ) /* non-rightmost page */
rbuf = _bt_getbuf(rel, lpageop->btpo_next, BT_WRITE); { /*
rpage = BufferGetPage(rbuf);
rpageop = (BTPageOpaque) PageGetSpecialPointer(rpage);
if ( P_RIGHTMOST (rpageop) )
{
Assert ( !( rpageop->btpo_flags & BTP_CHAIN ) );
use_left = false;
break;
}
/*
* If we have the same hikey here then it's * If we have the same hikey here then it's
* yet another page in chain and we may move * yet another page in chain.
* even righter. */
*/
if ( _bt_skeycmp (rel, keysz, scankey, rpage, if ( _bt_skeycmp (rel, keysz, scankey, rpage,
PageGetItemId(rpage, P_HIKEY), PageGetItemId(rpage, P_HIKEY),
BTEqualStrategyNumber) ) BTEqualStrategyNumber) )
@ -321,12 +312,12 @@ _bt_insertonpg(Relation rel,
keys_equal = true; keys_equal = true;
} }
else if ( _bt_skeycmp (rel, keysz, scankey, rpage, else if ( _bt_skeycmp (rel, keysz, scankey, rpage,
PageGetItemId(rpage, P_HIKEY), PageGetItemId(rpage, P_HIKEY),
BTGreaterStrategyNumber) ) BTGreaterStrategyNumber) )
elog (FATAL, "btree: hikey is out of order"); elog (FATAL, "btree: hikey is out of order");
/* /*
* If hikey > scankey and BTP_CHAIN is ON * If hikey > scankey and BTP_CHAIN is ON
* then it's first page of the chain of higher keys: * then it's first page of the chain of higher keys:
* our left sibling hikey was lying! We can't add new * our left sibling hikey was lying! We can't add new
* item here, but we can turn BTP_CHAIN off on our * item here, but we can turn BTP_CHAIN off on our
* left page and overwrite its hikey. * left page and overwrite its hikey.
@ -336,26 +327,19 @@ _bt_insertonpg(Relation rel,
BTItem tmp; BTItem tmp;
lpageop->btpo_flags &= ~BTP_CHAIN; lpageop->btpo_flags &= ~BTP_CHAIN;
tmp = (BTItem) PageGetItem(rpage, tmp = (BTItem) PageGetItem(rpage, PageGetItemId(rpage, P_HIKEY));
PageGetItemId(rpage, P_HIKEY));
hiRightItem = _bt_formitem(&(tmp->bti_itup)); hiRightItem = _bt_formitem(&(tmp->bti_itup));
break;
} }
/* /* if there is room here then we use this page. */
* if there is room here or hikey > scankey (so it's our else if ( PageGetFreeSpace (rpage) > itemsz )
* last page in the chain and we can't move righter) use_left = false;
* we have to use this page . }
*/ else /* rightmost page */
if ( PageGetFreeSpace (rpage) > itemsz || !keys_equal ) {
{ Assert ( !( rpageop->btpo_flags & BTP_CHAIN ) );
/* if there is room here then we use this page. */
if ( PageGetFreeSpace (rpage) > itemsz )
use_left = false; use_left = false;
break;
}
/* try to move righter */
_bt_relbuf(rel, buf, BT_WRITE);
buf = rbuf;
page = rpage;
lpageop = rpageop;
} }
if ( !use_left ) /* insert on the right page */ if ( !use_left ) /* insert on the right page */
{ {
@ -364,7 +348,6 @@ _bt_insertonpg(Relation rel,
scankey, btitem, afteritem) ); scankey, btitem, afteritem) );
} }
_bt_relbuf(rel, rbuf, BT_WRITE); _bt_relbuf(rel, rbuf, BT_WRITE);
bknum = BufferGetBlockNumber(buf);
} }
/* split the buffer into left and right halves */ /* split the buffer into left and right halves */