Revoke augmentation of WAL records for btree delete, per discussion.

This commit is contained in:
Simon Riggs 2010-02-01 13:40:28 +00:00
parent 9ea9918e37
commit 296578feb4
6 changed files with 14 additions and 48 deletions

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@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.247 2010/01/29 18:39:05 sriggs Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.248 2010/02/01 13:40:28 sriggs Exp $ -->
<chapter Id="runtime-config">
<title>Server Configuration</title>
@ -1840,22 +1840,6 @@ archive_command = 'copy "%p" "C:\\server\\archivedir\\%f"' # Windows
</listitem>
</varlistentry>
<varlistentry id="minimize-standby-conflicts" xreflabel="minimize_standby_conflicts">
<term><varname>minimize_standby_conflicts</varname> (<type>boolean</type>)</term>
<indexterm>
<primary><varname>minimize_standby_conflicts</> configuration parameter</primary>
</indexterm>
<listitem>
<para>
Generates additional information to the transaction log (WAL) to minimize
the number of false positive cancelations caused by recovery conflicts on
a standby server that consumes WAL data from this server.
There is additional performance cost to enabling this parameter.
Parameter has no effect during recovery, only in normal running.
</para>
</listitem>
</varlistentry>
</variablelist>
</sect2>
</sect1>

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@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/nbtree/nbtpage.c,v 1.116 2010/01/29 18:39:05 sriggs Exp $
* $PostgreSQL: pgsql/src/backend/access/nbtree/nbtpage.c,v 1.117 2010/02/01 13:40:28 sriggs Exp $
*
* NOTES
* Postgres btree pages look like ordinary relation pages. The opaque
@ -29,7 +29,6 @@
#include "storage/freespace.h"
#include "storage/indexfsm.h"
#include "storage/lmgr.h"
#include "storage/procarray.h"
#include "utils/inval.h"
#include "utils/snapmgr.h"
@ -672,18 +671,9 @@ _bt_delitems(Relation rel, Buffer buf,
{
Page page = BufferGetPage(buf);
BTPageOpaque opaque;
TransactionId latestRemovedXid = InvalidTransactionId;
Assert(isVacuum || lastBlockVacuumed == 0);
/*
* If allowed, calculate an accurate latestRemovedXid, otherwise
* pass InvalidTransactionId which can cause false positive
* conflicts to be assessed when we replay this WAL record.
*/
if (!isVacuum && XLogStandbyInfoActive() && MinimizeStandbyConflicts)
latestRemovedXid = GetOldestXmin(false, true);
/* No ereport(ERROR) until changes are logged */
START_CRIT_SECTION();
@ -731,7 +721,13 @@ _bt_delitems(Relation rel, Buffer buf,
xlrec_delete.node = rel->rd_node;
xlrec_delete.block = BufferGetBlockNumber(buf);
xlrec_delete.latestRemovedXid = latestRemovedXid;
/*
* XXX: We would like to set an accurate latestRemovedXid, but
* there is no easy way of obtaining a useful value. So we punt
* and store InvalidTransactionId, which forces the standby to
* wait for/cancel all currently running transactions.
*/
xlrec_delete.latestRemovedXid = InvalidTransactionId;
rdata[0].data = (char *) &xlrec_delete;
rdata[0].len = SizeOfBtreeDelete;
}

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@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.365 2010/01/29 18:39:05 sriggs Exp $
* $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.366 2010/02/01 13:40:28 sriggs Exp $
*
*-------------------------------------------------------------------------
*/
@ -71,7 +71,6 @@ bool XLogArchiveMode = false;
char *XLogArchiveCommand = NULL;
bool XLogRequestRecoveryConnections = true;
int MaxStandbyDelay = 30;
bool MinimizeStandbyConflicts = false;
bool fullPageWrites = true;
bool log_checkpoints = false;
int sync_method = DEFAULT_SYNC_METHOD;

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@ -10,7 +10,7 @@
* Written by Peter Eisentraut <peter_e@gmx.net>.
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.537 2010/01/29 18:39:05 sriggs Exp $
* $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.538 2010/02/01 13:40:28 sriggs Exp $
*
*--------------------------------------------------------------------
*/
@ -1222,17 +1222,6 @@ static struct config_bool ConfigureNamesBool[] =
true, NULL, NULL
},
{
{"minimize_standby_conflicts", PGC_POSTMASTER, WAL_SETTINGS,
gettext_noop("Additional information is added to WAL records to"
" minimize the number of false positive cancelations"
" caused by recovery conflicts on WAL standby nodes."),
NULL
},
&MinimizeStandbyConflicts,
false, NULL, NULL
},
{
{"allow_system_table_mods", PGC_POSTMASTER, DEVELOPER_OPTIONS,
gettext_noop("Allows modifications of the structure of system tables."),

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@ -184,9 +184,8 @@
# - Hot Standby -
#recovery_connections = on # allows connections during recovery
#minimize_standby_conflicts = on # additional WAL info to avoid conflicts
#max_standby_delay = 30 # max acceptable standby lag (s) to help queries
# complete without conflict; -1 disables
#max_standby_delay = 30 # max acceptable standby lag (s) to allow queries
# to complete without conflict; -1 disables
# - Replication -

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@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/access/xlog.h,v 1.100 2010/01/29 18:39:05 sriggs Exp $
* $PostgreSQL: pgsql/src/include/access/xlog.h,v 1.101 2010/02/01 13:40:28 sriggs Exp $
*/
#ifndef XLOG_H
#define XLOG_H
@ -183,7 +183,6 @@ extern int XLogArchiveTimeout;
extern bool log_checkpoints;
extern bool XLogRequestRecoveryConnections;
extern int MaxStandbyDelay;
extern bool MinimizeStandbyConflicts;
#define XLogArchivingActive() (XLogArchiveMode)
#define XLogArchiveCommandSet() (XLogArchiveCommand[0] != '\0')