rdelaage
/
postgresql
mirror of https://git.postgresql.org/git/postgresql.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
postgresql/src/include/access/commit_ts.h

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

75 lines
2.2 KiB
C
Raw Normal View History

Keep track of transaction commit timestamps Transactions can now set their commit timestamp directly as they commit, or an external transaction commit timestamp can be fed from an outside system using the new function TransactionTreeSetCommitTsData(). This data is crash-safe, and truncated at Xid freeze point, same as pg_clog. This module is disabled by default because it causes a performance hit, but can be enabled in postgresql.conf requiring only a server restart. A new test in src/test/modules is included. Catalog version bumped due to the new subdirectory within PGDATA and a couple of new SQL functions. Authors: Álvaro Herrera and Petr Jelínek Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven Singer, Peter Eisentraut
2014-12-03 15:53:02 +01:00
/*
* commit_ts.h
*
* PostgreSQL commit timestamp manager
*
Update copyright for 2023 Backpatch-through: 11
2023-01-02 21:00:37 +01:00
* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
Keep track of transaction commit timestamps Transactions can now set their commit timestamp directly as they commit, or an external transaction commit timestamp can be fed from an outside system using the new function TransactionTreeSetCommitTsData(). This data is crash-safe, and truncated at Xid freeze point, same as pg_clog. This module is disabled by default because it causes a performance hit, but can be enabled in postgresql.conf requiring only a server restart. A new test in src/test/modules is included. Catalog version bumped due to the new subdirectory within PGDATA and a couple of new SQL functions. Authors: Álvaro Herrera and Petr Jelínek Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven Singer, Peter Eisentraut
2014-12-03 15:53:02 +01:00
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/access/commit_ts.h
*/
#ifndef COMMIT_TS_H
#define COMMIT_TS_H
#include "access/xlog.h"
#include "datatype/timestamp.h"
Introduce replication progress tracking infrastructure. When implementing a replication solution ontop of logical decoding, two related problems exist: * How to safely keep track of replication progress * How to change replication behavior, based on the origin of a row; e.g. to avoid loops in bi-directional replication setups The solution to these problems, as implemented here, consist out of three parts: 1) 'replication origins', which identify nodes in a replication setup. 2) 'replication progress tracking', which remembers, for each replication origin, how far replay has progressed in a efficient and crash safe manner. 3) The ability to filter out changes performed on the behest of a replication origin during logical decoding; this allows complex replication topologies. E.g. by filtering all replayed changes out. Most of this could also be implemented in "userspace", e.g. by inserting additional rows contain origin information, but that ends up being much less efficient and more complicated. We don't want to require various replication solutions to reimplement logic for this independently. The infrastructure is intended to be generic enough to be reusable. This infrastructure also replaces the 'nodeid' infrastructure of commit timestamps. It is intended to provide all the former capabilities, except that there's only 2^16 different origins; but now they integrate with logical decoding. Additionally more functionality is accessible via SQL. Since the commit timestamp infrastructure has also been introduced in 9.5 (commit 73c986add) changing the API is not a problem. For now the number of origins for which the replication progress can be tracked simultaneously is determined by the max_replication_slots GUC. That GUC is not a perfect match to configure this, but there doesn't seem to be sufficient reason to introduce a separate new one. Bumps both catversion and wal page magic. Author: Andres Freund, with contributions from Petr Jelinek and Craig Ringer Reviewed-By: Heikki Linnakangas, Petr Jelinek, Robert Haas, Steve Singer Discussion: 20150216002155.GI15326@awork2.anarazel.de, 20140923182422.GA15776@alap3.anarazel.de, 20131114172632.GE7522@alap2.anarazel.de
2015-04-29 19:30:53 +02:00
#include "replication/origin.h"
Defer flushing of SLRU files. Previously, we called fsync() after writing out individual pg_xact, pg_multixact and pg_commit_ts pages due to cache pressure, leading to regular I/O stalls in user backends and recovery. Collapse requests for the same file into a single system call as part of the next checkpoint, as we already did for relation files, using the infrastructure developed by commit 3eb77eba. This can cause a significant improvement to recovery performance, especially when it's otherwise CPU-bound. Hoist ProcessSyncRequests() up into CheckPointGuts() to make it clearer that it applies to all the SLRU mini-buffer-pools as well as the main buffer pool. Rearrange things so that data collected in CheckpointStats includes SLRU activity. Also remove the Shutdown{CLOG,CommitTS,SUBTRANS,MultiXact}() functions, because they were redundant after the shutdown checkpoint that immediately precedes them. (I'm not sure if they were ever needed, but they aren't now.) Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> (parts) Tested-by: Jakub Wartak <Jakub.Wartak@tomtom.com> Discussion: https://postgr.es/m/CA+hUKGLJ=84YT+NvhkEEDAuUtVHMfQ9i-N7k_o50JmQ6Rpj_OQ@mail.gmail.com
2020-09-25 08:49:43 +02:00
#include "storage/sync.h"
Keep track of transaction commit timestamps Transactions can now set their commit timestamp directly as they commit, or an external transaction commit timestamp can be fed from an outside system using the new function TransactionTreeSetCommitTsData(). This data is crash-safe, and truncated at Xid freeze point, same as pg_clog. This module is disabled by default because it causes a performance hit, but can be enabled in postgresql.conf requiring only a server restart. A new test in src/test/modules is included. Catalog version bumped due to the new subdirectory within PGDATA and a couple of new SQL functions. Authors: Álvaro Herrera and Petr Jelínek Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven Singer, Peter Eisentraut
2014-12-03 15:53:02 +01:00
extern PGDLLIMPORT bool track_commit_timestamp;
extern void TransactionTreeSetCommitTsData(TransactionId xid, int nsubxids,
TransactionId *subxids, TimestampTz timestamp,
Remove COMMIT_TS_SETTS record. Commit 438fc4a39c prevented the WAL replay from writing COMMIT_TS_SETTS record. By this change there is no code that generates COMMIT_TS_SETTS record in PostgreSQL core. Also we can think that there are no extensions using the record because we've not received so far any complaints about the issue that commit 438fc4a39c fixed. Therefore this commit removes COMMIT_TS_SETTS record and its related code. Even without this record, the timestamp required for commit timestamp feature can be acquired from the COMMIT record. Bump WAL page magic. Reported-by: lx zou <zoulx1982@163.com> Author: Fujii Masao Reviewed-by: Alvaro Herrera Discussion: https://postgr.es/m/16931-620d0f2fdc6108f1@postgresql.org
2021-04-11 17:00:18 +02:00
RepOriginId nodeid);
Keep track of transaction commit timestamps Transactions can now set their commit timestamp directly as they commit, or an external transaction commit timestamp can be fed from an outside system using the new function TransactionTreeSetCommitTsData(). This data is crash-safe, and truncated at Xid freeze point, same as pg_clog. This module is disabled by default because it causes a performance hit, but can be enabled in postgresql.conf requiring only a server restart. A new test in src/test/modules is included. Catalog version bumped due to the new subdirectory within PGDATA and a couple of new SQL functions. Authors: Álvaro Herrera and Petr Jelínek Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven Singer, Peter Eisentraut
2014-12-03 15:53:02 +01:00
extern bool TransactionIdGetCommitTsData(TransactionId xid,
Introduce replication progress tracking infrastructure. When implementing a replication solution ontop of logical decoding, two related problems exist: * How to safely keep track of replication progress * How to change replication behavior, based on the origin of a row; e.g. to avoid loops in bi-directional replication setups The solution to these problems, as implemented here, consist out of three parts: 1) 'replication origins', which identify nodes in a replication setup. 2) 'replication progress tracking', which remembers, for each replication origin, how far replay has progressed in a efficient and crash safe manner. 3) The ability to filter out changes performed on the behest of a replication origin during logical decoding; this allows complex replication topologies. E.g. by filtering all replayed changes out. Most of this could also be implemented in "userspace", e.g. by inserting additional rows contain origin information, but that ends up being much less efficient and more complicated. We don't want to require various replication solutions to reimplement logic for this independently. The infrastructure is intended to be generic enough to be reusable. This infrastructure also replaces the 'nodeid' infrastructure of commit timestamps. It is intended to provide all the former capabilities, except that there's only 2^16 different origins; but now they integrate with logical decoding. Additionally more functionality is accessible via SQL. Since the commit timestamp infrastructure has also been introduced in 9.5 (commit 73c986add) changing the API is not a problem. For now the number of origins for which the replication progress can be tracked simultaneously is determined by the max_replication_slots GUC. That GUC is not a perfect match to configure this, but there doesn't seem to be sufficient reason to introduce a separate new one. Bumps both catversion and wal page magic. Author: Andres Freund, with contributions from Petr Jelinek and Craig Ringer Reviewed-By: Heikki Linnakangas, Petr Jelinek, Robert Haas, Steve Singer Discussion: 20150216002155.GI15326@awork2.anarazel.de, 20140923182422.GA15776@alap3.anarazel.de, 20131114172632.GE7522@alap2.anarazel.de
2015-04-29 19:30:53 +02:00
TimestampTz *ts, RepOriginId *nodeid);
Keep track of transaction commit timestamps Transactions can now set their commit timestamp directly as they commit, or an external transaction commit timestamp can be fed from an outside system using the new function TransactionTreeSetCommitTsData(). This data is crash-safe, and truncated at Xid freeze point, same as pg_clog. This module is disabled by default because it causes a performance hit, but can be enabled in postgresql.conf requiring only a server restart. A new test in src/test/modules is included. Catalog version bumped due to the new subdirectory within PGDATA and a couple of new SQL functions. Authors: Álvaro Herrera and Petr Jelínek Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven Singer, Peter Eisentraut
2014-12-03 15:53:02 +01:00
extern TransactionId GetLatestCommitTsData(TimestampTz *ts,
Introduce replication progress tracking infrastructure. When implementing a replication solution ontop of logical decoding, two related problems exist: * How to safely keep track of replication progress * How to change replication behavior, based on the origin of a row; e.g. to avoid loops in bi-directional replication setups The solution to these problems, as implemented here, consist out of three parts: 1) 'replication origins', which identify nodes in a replication setup. 2) 'replication progress tracking', which remembers, for each replication origin, how far replay has progressed in a efficient and crash safe manner. 3) The ability to filter out changes performed on the behest of a replication origin during logical decoding; this allows complex replication topologies. E.g. by filtering all replayed changes out. Most of this could also be implemented in "userspace", e.g. by inserting additional rows contain origin information, but that ends up being much less efficient and more complicated. We don't want to require various replication solutions to reimplement logic for this independently. The infrastructure is intended to be generic enough to be reusable. This infrastructure also replaces the 'nodeid' infrastructure of commit timestamps. It is intended to provide all the former capabilities, except that there's only 2^16 different origins; but now they integrate with logical decoding. Additionally more functionality is accessible via SQL. Since the commit timestamp infrastructure has also been introduced in 9.5 (commit 73c986add) changing the API is not a problem. For now the number of origins for which the replication progress can be tracked simultaneously is determined by the max_replication_slots GUC. That GUC is not a perfect match to configure this, but there doesn't seem to be sufficient reason to introduce a separate new one. Bumps both catversion and wal page magic. Author: Andres Freund, with contributions from Petr Jelinek and Craig Ringer Reviewed-By: Heikki Linnakangas, Petr Jelinek, Robert Haas, Steve Singer Discussion: 20150216002155.GI15326@awork2.anarazel.de, 20140923182422.GA15776@alap3.anarazel.de, 20131114172632.GE7522@alap2.anarazel.de
2015-04-29 19:30:53 +02:00
RepOriginId *nodeid);
Keep track of transaction commit timestamps Transactions can now set their commit timestamp directly as they commit, or an external transaction commit timestamp can be fed from an outside system using the new function TransactionTreeSetCommitTsData(). This data is crash-safe, and truncated at Xid freeze point, same as pg_clog. This module is disabled by default because it causes a performance hit, but can be enabled in postgresql.conf requiring only a server restart. A new test in src/test/modules is included. Catalog version bumped due to the new subdirectory within PGDATA and a couple of new SQL functions. Authors: Álvaro Herrera and Petr Jelínek Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven Singer, Peter Eisentraut
2014-12-03 15:53:02 +01:00
extern Size CommitTsShmemBuffers(void);
extern Size CommitTsShmemSize(void);
extern void CommitTsShmemInit(void);
extern void BootStrapCommitTs(void);
Fix commit timestamp initialization This module needs explicit initialization in order to replay WAL records in recovery, but we had broken this recently following changes to make other (stranger) scenarios work correctly. To fix, rework the initialization sequence so that it always takes place before WAL replay commences for both master and standby. I could have gone for a more localized fix that just added a "startup" call for the master server, but it seemed better to restructure the existing callers as well so that the whole thing made more sense. As a drawback, there is more control logic in xlog.c now than previously, but doing otherwise meant passing down the ControlFile flag, which seemed uglier as a whole. This also meant adding a check to not re-execute ActivateCommitTs if it had already been called. Reported by Fujii Masao. Backpatch to 9.5.
2015-12-11 18:30:43 +01:00
extern void StartupCommitTs(void);
Fix inconsistencies and typos in the tree, take 9 This addresses more issues with code comments, variable names and unreferenced variables. Author: Alexander Lakhin Discussion: https://postgr.es/m/7ab243e0-116d-3e44-d120-76b3df7abefd@gmail.com
2019-08-05 05:14:58 +02:00
extern void CommitTsParameterChange(bool newvalue, bool oldvalue);
Keep track of transaction commit timestamps Transactions can now set their commit timestamp directly as they commit, or an external transaction commit timestamp can be fed from an outside system using the new function TransactionTreeSetCommitTsData(). This data is crash-safe, and truncated at Xid freeze point, same as pg_clog. This module is disabled by default because it causes a performance hit, but can be enabled in postgresql.conf requiring only a server restart. A new test in src/test/modules is included. Catalog version bumped due to the new subdirectory within PGDATA and a couple of new SQL functions. Authors: Álvaro Herrera and Petr Jelínek Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven Singer, Peter Eisentraut
2014-12-03 15:53:02 +01:00
extern void CompleteCommitTsInitialization(void);
extern void CheckPointCommitTs(void);
extern void ExtendCommitTs(TransactionId newestXact);
Cleanup commit timestamp module activaction, again Further tweak commit_ts.c so that on a standby the state is completely consistent with what that in the master, rather than behaving differently in the cases that the settings differ. Now in standby and master the module should always be active or inactive in lockstep. Author: Petr Jelínek, with some further tweaks by Álvaro Herrera. Backpatch to 9.5, where commit timestamps were introduced. Discussion: http://www.postgresql.org/message-id/5622BF9D.2010409@2ndquadrant.com
2015-10-27 19:06:50 +01:00
extern void TruncateCommitTs(TransactionId oldestXact);
Keep track of transaction commit timestamps Transactions can now set their commit timestamp directly as they commit, or an external transaction commit timestamp can be fed from an outside system using the new function TransactionTreeSetCommitTsData(). This data is crash-safe, and truncated at Xid freeze point, same as pg_clog. This module is disabled by default because it causes a performance hit, but can be enabled in postgresql.conf requiring only a server restart. A new test in src/test/modules is included. Catalog version bumped due to the new subdirectory within PGDATA and a couple of new SQL functions. Authors: Álvaro Herrera and Petr Jelínek Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven Singer, Peter Eisentraut
2014-12-03 15:53:02 +01:00
extern void SetCommitTsLimit(TransactionId oldestXact,
TransactionId newestXact);
Rename (new|old)estCommitTs to (new|old)estCommitTsXid The variables newestCommitTs and oldestCommitTs sound as if they are timestamps, but in fact they are the transaction Ids that correspond to the newest and oldest timestamps rather than the actual timestamps. Rename these variables to reflect that they are actually xids: to wit newestCommitTsXid and oldestCommitTsXid respectively. Also modify related code in a similar fashion, particularly the user facing output emitted by pg_controldata and pg_resetxlog. Complaint and patch by me, review by Tom Lane and Alvaro Herrera. Backpatch to 9.5 where these variables were first introduced.
2015-12-28 21:34:11 +01:00
extern void AdvanceOldestCommitTsXid(TransactionId oldestXact);
Keep track of transaction commit timestamps Transactions can now set their commit timestamp directly as they commit, or an external transaction commit timestamp can be fed from an outside system using the new function TransactionTreeSetCommitTsData(). This data is crash-safe, and truncated at Xid freeze point, same as pg_clog. This module is disabled by default because it causes a performance hit, but can be enabled in postgresql.conf requiring only a server restart. A new test in src/test/modules is included. Catalog version bumped due to the new subdirectory within PGDATA and a couple of new SQL functions. Authors: Álvaro Herrera and Petr Jelínek Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven Singer, Peter Eisentraut
2014-12-03 15:53:02 +01:00
Defer flushing of SLRU files. Previously, we called fsync() after writing out individual pg_xact, pg_multixact and pg_commit_ts pages due to cache pressure, leading to regular I/O stalls in user backends and recovery. Collapse requests for the same file into a single system call as part of the next checkpoint, as we already did for relation files, using the infrastructure developed by commit 3eb77eba. This can cause a significant improvement to recovery performance, especially when it's otherwise CPU-bound. Hoist ProcessSyncRequests() up into CheckPointGuts() to make it clearer that it applies to all the SLRU mini-buffer-pools as well as the main buffer pool. Rearrange things so that data collected in CheckpointStats includes SLRU activity. Also remove the Shutdown{CLOG,CommitTS,SUBTRANS,MultiXact}() functions, because they were redundant after the shutdown checkpoint that immediately precedes them. (I'm not sure if they were ever needed, but they aren't now.) Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> (parts) Tested-by: Jakub Wartak <Jakub.Wartak@tomtom.com> Discussion: https://postgr.es/m/CA+hUKGLJ=84YT+NvhkEEDAuUtVHMfQ9i-N7k_o50JmQ6Rpj_OQ@mail.gmail.com
2020-09-25 08:49:43 +02:00
extern int committssyncfiletag(const FileTag *ftag, char *path);
Keep track of transaction commit timestamps Transactions can now set their commit timestamp directly as they commit, or an external transaction commit timestamp can be fed from an outside system using the new function TransactionTreeSetCommitTsData(). This data is crash-safe, and truncated at Xid freeze point, same as pg_clog. This module is disabled by default because it causes a performance hit, but can be enabled in postgresql.conf requiring only a server restart. A new test in src/test/modules is included. Catalog version bumped due to the new subdirectory within PGDATA and a couple of new SQL functions. Authors: Álvaro Herrera and Petr Jelínek Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven Singer, Peter Eisentraut
2014-12-03 15:53:02 +01:00
/* XLOG stuff */
#define COMMIT_TS_ZEROPAGE 0x00
#define COMMIT_TS_TRUNCATE 0x10
typedef struct xl_commit_ts_set
{
TimestampTz timestamp;
Introduce replication progress tracking infrastructure. When implementing a replication solution ontop of logical decoding, two related problems exist: * How to safely keep track of replication progress * How to change replication behavior, based on the origin of a row; e.g. to avoid loops in bi-directional replication setups The solution to these problems, as implemented here, consist out of three parts: 1) 'replication origins', which identify nodes in a replication setup. 2) 'replication progress tracking', which remembers, for each replication origin, how far replay has progressed in a efficient and crash safe manner. 3) The ability to filter out changes performed on the behest of a replication origin during logical decoding; this allows complex replication topologies. E.g. by filtering all replayed changes out. Most of this could also be implemented in "userspace", e.g. by inserting additional rows contain origin information, but that ends up being much less efficient and more complicated. We don't want to require various replication solutions to reimplement logic for this independently. The infrastructure is intended to be generic enough to be reusable. This infrastructure also replaces the 'nodeid' infrastructure of commit timestamps. It is intended to provide all the former capabilities, except that there's only 2^16 different origins; but now they integrate with logical decoding. Additionally more functionality is accessible via SQL. Since the commit timestamp infrastructure has also been introduced in 9.5 (commit 73c986add) changing the API is not a problem. For now the number of origins for which the replication progress can be tracked simultaneously is determined by the max_replication_slots GUC. That GUC is not a perfect match to configure this, but there doesn't seem to be sufficient reason to introduce a separate new one. Bumps both catversion and wal page magic. Author: Andres Freund, with contributions from Petr Jelinek and Craig Ringer Reviewed-By: Heikki Linnakangas, Petr Jelinek, Robert Haas, Steve Singer Discussion: 20150216002155.GI15326@awork2.anarazel.de, 20140923182422.GA15776@alap3.anarazel.de, 20131114172632.GE7522@alap2.anarazel.de
2015-04-29 19:30:53 +02:00
RepOriginId nodeid;
Keep track of transaction commit timestamps Transactions can now set their commit timestamp directly as they commit, or an external transaction commit timestamp can be fed from an outside system using the new function TransactionTreeSetCommitTsData(). This data is crash-safe, and truncated at Xid freeze point, same as pg_clog. This module is disabled by default because it causes a performance hit, but can be enabled in postgresql.conf requiring only a server restart. A new test in src/test/modules is included. Catalog version bumped due to the new subdirectory within PGDATA and a couple of new SQL functions. Authors: Álvaro Herrera and Petr Jelínek Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven Singer, Peter Eisentraut
2014-12-03 15:53:02 +01:00
TransactionId mainxid;
/* subxact Xids follow */
} xl_commit_ts_set;
#define SizeOfCommitTsSet (offsetof(xl_commit_ts_set, mainxid) + \
sizeof(TransactionId))
Fix race condition in reading commit timestamps If a user requests the commit timestamp for a transaction old enough that its data is concurrently being truncated away by vacuum at just the right time, they would receive an ugly internal file-not-found error message from slru.c rather than the expected NULL return value. In a primary server, the window for the race is very small: the lookup has to occur exactly between the two calls by vacuum, and there's not a lot that happens between them (mostly just a multixact truncate). In a standby server, however, the window is larger because the truncation is executed as soon as the WAL record for it is replayed, but the advance of the oldest-Xid is not executed until the next checkpoint record. To fix in the primary, simply reverse the order of operations in vac_truncate_clog. To fix in the standby, augment the WAL truncation record so that the standby is aware of the new oldest-XID value and can apply the update immediately. WAL version bumped because of this. No backpatch, because of the low importance of the bug and its rarity. Author: Craig Ringer Reviewed-By: Petr Jelínek, Peter Eisentraut Discussion: https://postgr.es/m/CAMsr+YFhVtRQT1VAwC+WGbbxZZRzNou=N9Ed-FrCqkwQ8H8oJQ@mail.gmail.com
2017-01-19 22:23:09 +01:00
typedef struct xl_commit_ts_truncate
{
int pageno;
TransactionId oldestXid;
} xl_commit_ts_truncate;
#define SizeOfCommitTsTruncate (offsetof(xl_commit_ts_truncate, oldestXid) + \
sizeof(TransactionId))
Keep track of transaction commit timestamps Transactions can now set their commit timestamp directly as they commit, or an external transaction commit timestamp can be fed from an outside system using the new function TransactionTreeSetCommitTsData(). This data is crash-safe, and truncated at Xid freeze point, same as pg_clog. This module is disabled by default because it causes a performance hit, but can be enabled in postgresql.conf requiring only a server restart. A new test in src/test/modules is included. Catalog version bumped due to the new subdirectory within PGDATA and a couple of new SQL functions. Authors: Álvaro Herrera and Petr Jelínek Reviewed to varying degrees by Michael Paquier, Andres Freund, Robert Haas, Amit Kapila, Fujii Masao, Jaime Casanova, Simon Riggs, Steven Singer, Peter Eisentraut
2014-12-03 15:53:02 +01:00
extern void commit_ts_redo(XLogReaderState *record);
extern void commit_ts_desc(StringInfo buf, XLogReaderState *record);
extern const char *commit_ts_identify(uint8 info);
Code review for transaction commit timestamps There are three main changes here: 1. No longer cause a start failure in a standby if the feature is disabled in postgresql.conf but enabled in the master. This reverts one part of commit 4f3924d9cd43; what we keep is the ability of the standby to activate/deactivate the module (which includes creating and removing segments as appropriate) during replay of such actions in the master. 2. Replay WAL records affecting commitTS even if the feature is disabled. This means the standby will always have the same state as the master after replay. 3. Have COMMIT PREPARE record the transaction commit time as well. We were previously only applying it in the normal transaction commit path. Author: Petr Jelínek Discussion: http://www.postgresql.org/message-id/CAHGQGwHereDzzzmfxEBYcVQu3oZv6vZcgu1TPeERWbDc+gQ06g@mail.gmail.com Discussion: http://www.postgresql.org/message-id/CAHGQGwFuzfO4JscM9LCAmCDCxp_MfLvN4QdB+xWsS-FijbjTYQ@mail.gmail.com Additionally, I cleaned up nearby code related to replication origins, which I found a bit hard to follow, and fixed a couple of typos. Backpatch to 9.5, where this code was introduced. Per bug reports from Fujii Masao and subsequent discussion.
2015-09-29 19:40:56 +02:00
#endif /* COMMIT_TS_H */