From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 21 Feb 2003 18:24:54 +0000 (+0000)
Subject: Repair nasty oversight in bt_split: if the index is temporary, we weren't
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=1eb767fb8d0aa1d46a1230b101c70053adf2ae6f;p=users%2Fbernd%2Fpostgres.git

Repair nasty oversight in bt_split: if the index is temporary, we weren't
updating the left-link from the split page's right sibling.  This could
result in backwards index scans missing some entries.
Same bug exists in HEAD, will be patched later.
---

diff --git a/src/backend/access/nbtree/nbtinsert.c b/src/backend/access/nbtree/nbtinsert.c
index ac319ffede..a2c5d4d0f9 100644
--- a/src/backend/access/nbtree/nbtinsert.c
+++ b/src/backend/access/nbtree/nbtinsert.c
@@ -699,6 +699,7 @@ _bt_split(Relation rel, Buffer buf, OffsetNumber firstright,
 				oopaque;
 	Buffer		sbuf = 0;
 	Page		spage = 0;
+	BTPageOpaque sopaque = 0;
 	Size		itemsz;
 	ItemId		itemid;
 	BTItem		item;
@@ -862,6 +863,7 @@ _bt_split(Relation rel, Buffer buf, OffsetNumber firstright,
 	{
 		sbuf = _bt_getbuf(rel, ropaque->btpo_next, BT_WRITE);
 		spage = BufferGetPage(sbuf);
+		sopaque = (BTPageOpaque) PageGetSpecialPointer(spage);
 	}
 
 	/*
@@ -872,6 +874,9 @@ _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)
 	{
@@ -922,10 +927,6 @@ _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;