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postgresql/src/include/access/twophase.h

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Two-phase commit. Original patch by Heikki Linnakangas, with additional hacking by Alvaro Herrera and Tom Lane.
2005-06-18 00:32:51 +02:00
/*-------------------------------------------------------------------------
*
* twophase.h
* Two-phase-commit related declarations.
*
*
Update copyright for the year 2010.
2010-01-02 17:58:17 +01:00
* Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
Two-phase commit. Original patch by Heikki Linnakangas, with additional hacking by Alvaro Herrera and Tom Lane.
2005-06-18 00:32:51 +02:00
* Portions Copyright (c) 1994, Regents of the University of California
*
Allow Hot Standby to begin from a shutdown checkpoint. Patch by Simon Riggs & me
2010-04-13 16:17:46 +02:00
* $PostgreSQL: pgsql/src/include/access/twophase.h,v 1.15 2010/04/13 14:17:46 heikki Exp $
Two-phase commit. Original patch by Heikki Linnakangas, with additional hacking by Alvaro Herrera and Tom Lane.
2005-06-18 00:32:51 +02:00
*
*-------------------------------------------------------------------------
*/
#ifndef TWOPHASE_H
#define TWOPHASE_H
Allow include files to compile own their own. Strip unused include files out unused include files, and add needed includes to C files. The next step is to remove unused include files in C files.
2006-07-13 18:49:20 +02:00
#include "access/xlogdefs.h"
Fix an old bug in multixact and two-phase commit. Prepared transactions can be part of multixacts, so allocate a slot for each prepared transaction in the "oldest member" array in multixact.c. On PREPARE TRANSACTION, transfer the oldest member value from the current backends slot to the prepared xact slot. Also save and recover the value from the 2pc state file. The symptom of the bug was that after a transaction prepared, a shared lock still held by the prepared transaction was sometimes ignored by other transactions. Fix back to 8.1, where both 2PC and multixact were introduced.
2009-11-23 10:58:36 +01:00
#include "storage/backendid.h"
Arrange to fsync two-phase-commit state files only during checkpoints; given reasonably short lifespans for prepared transactions, this should mean that only a small minority of state files ever need to be fsynced at all. Per discussion with Heikki Linnakangas.
2005-06-19 22:00:39 +02:00
#include "storage/proc.h"
Add a time-of-preparation column to the pg_prepared_xacts view, per an old suggestion by Oliver Jowett. Also, add a transaction column to the pg_locks view to show the xid of each transaction holding or awaiting locks; this allows prepared transactions to be properly associated with the locks they own. There was already a column named 'transaction', and I chose to rename it to 'transactionid' --- since this column is new in the current devel cycle there should be no backwards compatibility issue to worry about.
2005-06-18 21:33:42 +02:00
#include "utils/timestamp.h"
Two-phase commit. Original patch by Heikki Linnakangas, with additional hacking by Alvaro Herrera and Tom Lane.
2005-06-18 00:32:51 +02:00
/*
* GlobalTransactionData is defined in twophase.c; other places have no
* business knowing the internal definition.
*/
typedef struct GlobalTransactionData *GlobalTransaction;
/* GUC variable */
Standard pgindent run for 8.1.
2005-10-15 04:49:52 +02:00
extern int max_prepared_xacts;
Two-phase commit. Original patch by Heikki Linnakangas, with additional hacking by Alvaro Herrera and Tom Lane.
2005-06-18 00:32:51 +02:00
Convert the arithmetic for shared memory size calculation from 'int' to 'Size' (that is, size_t), and install overflow detection checks in it. This allows us to remove the former arbitrary restrictions on NBuffers etc. It won't make any difference in a 32-bit machine, but in a 64-bit machine you could theoretically have terabytes of shared buffers. (How efficiently we could manage 'em remains to be seen.) Similarly, num_temp_buffers, work_mem, and maintenance_work_mem can be set above 2Gb on a 64-bit machine. Original patch from Koichi Suzuki, additional work by moi.
2005-08-21 01:26:37 +02:00
extern Size TwoPhaseShmemSize(void);
Two-phase commit. Original patch by Heikki Linnakangas, with additional hacking by Alvaro Herrera and Tom Lane.
2005-06-18 00:32:51 +02:00
extern void TwoPhaseShmemInit(void);
extern PGPROC *TwoPhaseGetDummyProc(TransactionId xid);
Fix an old bug in multixact and two-phase commit. Prepared transactions can be part of multixacts, so allocate a slot for each prepared transaction in the "oldest member" array in multixact.c. On PREPARE TRANSACTION, transfer the oldest member value from the current backends slot to the prepared xact slot. Also save and recover the value from the 2pc state file. The symptom of the bug was that after a transaction prepared, a shared lock still held by the prepared transaction was sometimes ignored by other transactions. Fix back to 8.1, where both 2PC and multixact were introduced.
2009-11-23 10:58:36 +01:00
extern BackendId TwoPhaseGetDummyBackendId(TransactionId xid);
Two-phase commit. Original patch by Heikki Linnakangas, with additional hacking by Alvaro Herrera and Tom Lane.
2005-06-18 00:32:51 +02:00
Add a time-of-preparation column to the pg_prepared_xacts view, per an old suggestion by Oliver Jowett. Also, add a transaction column to the pg_locks view to show the xid of each transaction holding or awaiting locks; this allows prepared transactions to be properly associated with the locks they own. There was already a column named 'transaction', and I chose to rename it to 'transactionid' --- since this column is new in the current devel cycle there should be no backwards compatibility issue to worry about.
2005-06-18 21:33:42 +02:00
extern GlobalTransaction MarkAsPreparing(TransactionId xid, const char *gid,
Standard pgindent run for 8.1.
2005-10-15 04:49:52 +02:00
TimestampTz prepared_at,
Oid owner, Oid databaseid);
Two-phase commit. Original patch by Heikki Linnakangas, with additional hacking by Alvaro Herrera and Tom Lane.
2005-06-18 00:32:51 +02:00
extern void StartPrepare(GlobalTransaction gxact);
extern void EndPrepare(GlobalTransaction gxact);
Allow read only connections during recovery, known as Hot Standby. Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record. New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far. This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required. Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit. Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
extern bool StandbyTransactionIdIsPrepared(TransactionId xid);
Two-phase commit. Original patch by Heikki Linnakangas, with additional hacking by Alvaro Herrera and Tom Lane.
2005-06-18 00:32:51 +02:00
Allow read only connections during recovery, known as Hot Standby. Enabled by recovery_connections = on (default) and forcing archive recovery using a recovery.conf. Recovery processing now emulates the original transactions as they are replayed, providing full locking and MVCC behaviour for read only queries. Recovery must enter consistent state before connections are allowed, so there is a delay, typically short, before connections succeed. Replay of recovering transactions can conflict and in some cases deadlock with queries during recovery; these result in query cancellation after max_standby_delay seconds have expired. Infrastructure changes have minor effects on normal running, though introduce four new types of WAL record. New test mode "make standbycheck" allows regression tests of static command behaviour on a standby server while in recovery. Typical and extreme dynamic behaviours have been checked via code inspection and manual testing. Few port specific behaviours have been utilised, though primary testing has been on Linux only so far. This commit is the basic patch. Additional changes will follow in this release to enhance some aspects of behaviour, notably improved handling of conflicts, deadlock detection and query cancellation. Changes to VACUUM FULL are also required. Simon Riggs, with significant and lengthy review by Heikki Linnakangas, including streamlined redesign of snapshot creation and two-phase commit. Important contributions from Florian Pflug, Mark Kirkwood, Merlin Moncure, Greg Stark, Gianni Ciolli, Gabriele Bartolini, Hannu Krosing, Robert Haas, Tatsuo Ishii, Hiroyuki Yamada plus support and feedback from many other community members.
2009-12-19 02:32:45 +01:00
extern TransactionId PrescanPreparedTransactions(TransactionId **xids_p,
int *nxids_p);
Allow Hot Standby to begin from a shutdown checkpoint. Patch by Simon Riggs & me
2010-04-13 16:17:46 +02:00
extern void StandbyRecoverPreparedTransactions(bool overwriteOK);
Two-phase commit. Original patch by Heikki Linnakangas, with additional hacking by Alvaro Herrera and Tom Lane.
2005-06-18 00:32:51 +02:00
extern void RecoverPreparedTransactions(void);
extern void RecreateTwoPhaseFile(TransactionId xid, void *content, int len);
extern void RemoveTwoPhaseFile(TransactionId xid, bool giveWarning);
Arrange to fsync two-phase-commit state files only during checkpoints; given reasonably short lifespans for prepared transactions, this should mean that only a small minority of state files ever need to be fsynced at all. Per discussion with Heikki Linnakangas.
2005-06-19 22:00:39 +02:00
extern void CheckPointTwoPhase(XLogRecPtr redo_horizon);
Add a time-of-preparation column to the pg_prepared_xacts view, per an old suggestion by Oliver Jowett. Also, add a transaction column to the pg_locks view to show the xid of each transaction holding or awaiting locks; this allows prepared transactions to be properly associated with the locks they own. There was already a column named 'transaction', and I chose to rename it to 'transactionid' --- since this column is new in the current devel cycle there should be no backwards compatibility issue to worry about.
2005-06-18 21:33:42 +02:00
extern void FinishPreparedTransaction(const char *gid, bool isCommit);
Two-phase commit. Original patch by Heikki Linnakangas, with additional hacking by Alvaro Herrera and Tom Lane.
2005-06-18 00:32:51 +02:00
#endif /* TWOPHASE_H */