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Fix duplicating ROOT page in concurrent updates.

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This commit is contained in:
Vadim B. Mikheev 1999-04-22 08:19:59 +00:00
parent 00fbb64bed
commit 3888b53a58
2 changed files with 41 additions and 16 deletions
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16
src/backend/access/nbtree/nbtinsert.c
View File

@ -7,7 +7,7 @@
* *
* *
* IDENTIFICATION * IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.37 1999/04/12 16:56:08 vadim Exp $ * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.38 1999/04/22 08:19:59 vadim Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -398,6 +398,7 @@ _bt_insertonpg(Relation rel,
OffsetNumber maxoff; OffsetNumber maxoff;
bool shifted = false; bool shifted = false;
bool left_chained = (lpageop->btpo_flags & BTP_CHAIN) ? true : false; bool left_chained = (lpageop->btpo_flags & BTP_CHAIN) ? true : false;
bool is_root = lpageop->btpo_flags & BTP_ROOT;
/* /*
* If we have to split leaf page in the chain of duplicates by new * If we have to split leaf page in the chain of duplicates by new
@ -570,9 +571,20 @@ _bt_insertonpg(Relation rel,
* reasoning). * reasoning).
*/ */
l_spl:;
if (stack == (BTStack) NULL) if (stack == (BTStack) NULL)
{ {
if (!is_root) /* if this page was not root page */
{
elog(DEBUG, "btree: concurrent ROOT page split");
stack = (BTStack) palloc(sizeof(BTStackData));
stack->bts_blkno = lpageop->btpo_parent;
stack->bts_offset = InvalidOffsetNumber;
stack->bts_btitem = (BTItem) palloc(sizeof(BTItemData));
/* bts_btitem will be initialized below */
stack->bts_parent = NULL;
goto l_spl;
}
/* create a new root node and release the split buffers */ /* create a new root node and release the split buffers */
_bt_newroot(rel, buf, rbuf); _bt_newroot(rel, buf, rbuf);
_bt_relbuf(rel, buf, BT_WRITE); _bt_relbuf(rel, buf, BT_WRITE);

41
src/backend/access/nbtree/nbtpage.c
View File

@ -8,7 +8,7 @@
* *
* *
* IDENTIFICATION * IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtpage.c,v 1.19 1999/03/28 20:31:57 vadim Exp $ * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtpage.c,v 1.20 1999/04/22 08:19:59 vadim Exp $
* *
* NOTES * NOTES
* Postgres btree pages look like ordinary relation pages. The opaque * Postgres btree pages look like ordinary relation pages. The opaque
@ -494,24 +494,37 @@ _bt_getstackbuf(Relation rel, BTStack stack, int access)
opaque = (BTPageOpaque) PageGetSpecialPointer(page); opaque = (BTPageOpaque) PageGetSpecialPointer(page);
maxoff = PageGetMaxOffsetNumber(page); maxoff = PageGetMaxOffsetNumber(page);
if (maxoff >= stack->bts_offset) if (stack->bts_offset == InvalidOffsetNumber ||
maxoff >= stack->bts_offset)
{ {
itemid = PageGetItemId(page, stack->bts_offset); /*
item = (BTItem) PageGetItem(page, itemid); * _bt_insertonpg set bts_offset to InvalidOffsetNumber
* in the case of concurrent ROOT page split
/* if the item is where we left it, we're done */ */
if (BTItemSame(item, stack->bts_btitem)) if (stack->bts_offset == InvalidOffsetNumber)
{ {
pfree(stack->bts_btitem); i = P_RIGHTMOST(opaque) ? P_HIKEY : P_FIRSTKEY;
item_nbytes = ItemIdGetLength(itemid); }
item_save = (BTItem) palloc(item_nbytes); else
memmove((char *) item_save, (char *) item, item_nbytes); {
stack->bts_btitem = item_save; itemid = PageGetItemId(page, stack->bts_offset);
return buf; item = (BTItem) PageGetItem(page, itemid);
/* if the item is where we left it, we're done */
if (BTItemSame(item, stack->bts_btitem))
{
pfree(stack->bts_btitem);
item_nbytes = ItemIdGetLength(itemid);
item_save = (BTItem) palloc(item_nbytes);
memmove((char *) item_save, (char *) item, item_nbytes);
stack->bts_btitem = item_save;
return buf;
}
i = OffsetNumberNext(stack->bts_offset);
} }
/* if the item has just moved right on this page, we're done */ /* if the item has just moved right on this page, we're done */
for (i = OffsetNumberNext(stack->bts_offset); for ( ;
i <= maxoff; i <= maxoff;
i = OffsetNumberNext(i)) i = OffsetNumberNext(i))
{ {