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path: root/src/backend/access/transam/clog.c
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2010-01-02Update copyright for the year 2010.Bruce Momjian
2009-12-19Allow read only connections during recovery, known as Hot Standby.Simon Riggs
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.
2009-06-118.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef listBruce Momjian
provided by Andrew.
2009-01-20Add a new option to RestoreBkpBlocks() to indicate if a cleanup lock shouldHeikki Linnakangas
be used instead of the normal exclusive lock, and make WAL redo functions responsible for calling RestoreBkpBlocks(). They know better what kind of a lock they need. At the moment, this just moves things around with no functional change, but makes the hot standby patch that's under review cleaner.
2009-01-01Update copyright for 2009.Bruce Momjian
2008-11-03Fix silly typo in previous commit.Alvaro Herrera
2008-11-03Fix TransactionIdSetStatusBit so that it doesn't try to change a transactionAlvaro Herrera
from COMMITTED to SUBCOMMITTED during recovery. This wasn't previously possible, but it is now due to the recent changes on clog commit protocol for subtransactions. Simon Riggs
2008-10-20Rework subtransaction commit protocol for hot standby.Alvaro Herrera
This patch eliminates the marking of subtransactions as SUBCOMMITTED in pg_clog during their commit; instead they remain in-progress until main transaction commit. At main transaction commit, the commit protocol is atomic-by-page instead of one transaction at a time. To avoid a race condition with some subtransactions appearing committed before others in the case where they span more than one pg_clog page, we conserve the logic that marks them subcommitted before marking the parent committed. Simon Riggs with minor help from me
2008-08-01Add a few more DTrace probes to the backend.Alvaro Herrera
Robert Lor
2008-01-01Update copyrights in source tree to 2008.Bruce Momjian
2007-11-15pgindent run for 8.3.Bruce Momjian
2007-09-05Implement lazy XID allocation: transactions that do not modify any databaseTom Lane
rows will normally never obtain an XID at all. We already did things this way for subtransactions, but this patch extends the concept to top-level transactions. In applications where there are lots of short read-only transactions, this should improve performance noticeably; not so much from removal of the actual XID-assignments, as from reduction of overhead that's driven by the rate of XID consumption. We add a concept of a "virtual transaction ID" so that active transactions can be uniquely identified even if they don't have a regular XID. This is a much lighter-weight concept: uniqueness of VXIDs is only guaranteed over the short term, and no on-disk record is made about them. Florian Pflug, with some editorialization by Tom.
2007-08-01Support an optional asynchronous commit mode, in which we don't flush WALTom Lane
before reporting a transaction committed. Data consistency is still guaranteed (unlike setting fsync = off), but a crash may lose the effects of the last few transactions. Patch by Simon, some editorialization by Tom.
2007-01-05Update CVS HEAD for 2007 copyright. Back branches are typically notBruce Momjian
back-stamped for this.
2006-11-05Fix recently-understood problems with handling of XID freezing, particularlyTom Lane
in PITR scenarios. We now WAL-log the replacement of old XIDs with FrozenTransactionId, so that such replacement is guaranteed to propagate to PITR slave databases. Also, rather than relying on hint-bit updates to be preserved, pg_clog is not truncated until all instances of an XID are known to have been replaced by FrozenTransactionId. Add new GUC variables and pg_autovacuum columns to allow management of the freezing policy, so that users can trade off the size of pg_clog against the amount of freezing work done. Revise the already-existing code that forces autovacuum of tables approaching the wraparound point to make it more bulletproof; also, revise the autovacuum logic so that anti-wraparound vacuuming is done per-table rather than per-database. initdb forced because of changes in pg_class, pg_database, and pg_autovacuum catalogs. Heikki Linnakangas, Simon Riggs, and Tom Lane.
2006-10-04pgindent run for 8.2.Bruce Momjian
2006-07-13Allow include files to compile own their own.Bruce Momjian
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.
2006-03-24Arrange to emit a description of the current XLOG record as error contextTom Lane
when an error occurs during xlog replay. Also, replace the former risky 'write into a fixed-size buffer with no overflow detection' API for XLOG record description routines; use an expansible StringInfo instead. (The latter accounts for most of the patch bulk.) Qingqing Zhou
2006-03-05Update copyright for 2006. Update scripts.Bruce Momjian
2005-12-06Get rid of slru.c's hardwired insistence on a fixed number of slots perTom Lane
SLRU area. The number of slots is still a compile-time constant (someday we might want to change that), but at least it's a different constant for each SLRU area. Increase number of subtrans buffers to 32 based on experimentation with a heavily subtrans-bashing test case, and increase number of multixact member buffers to 16, since it's obviously silly for it not to be at least twice the number of multixact offset buffers.
2005-12-06Arrange for read-only accesses to SLRU page buffers to take only a sharedTom Lane
lock, not exclusive, if the desired page is already in memory. This can be demonstrated to be a significant win on the pg_subtrans cache when there is a large window of open transactions. It should be useful for pg_clog as well. I didn't try to make GetMultiXactIdMembers() use the code, as that would have taken some restructuring, and what with the local cache for multixact contents it probably wouldn't really make a difference. Per my recent proposal.
2005-11-05Clean up representation of SLRU page state. This is the cleaner fixTom Lane
for the SLRU race condition that I posted a few days ago, but we decided not to use in 8.1 and older branches.
2005-10-15Standard pgindent run for 8.1.Bruce Momjian
2005-08-20Convert the arithmetic for shared memory size calculation from 'int'Tom Lane
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.
2005-06-30Improve the checkpoint signaling mechanism so that the bgwriter can tellTom Lane
the difference between checkpoints forced due to WAL segment consumption and checkpoints forced for other reasons (such as CREATE DATABASE). Avoid generating 'checkpoints are occurring too frequently' messages when the checkpoint wasn't caused by WAL segment consumption. Per gripe from Chris K-L.
2005-06-06Modify XLogInsert API to make callers specify whether pages to be backedTom Lane
up have the standard layout with unused space between pd_lower and pd_upper. When this is set, XLogInsert will omit the unused space without bothering to scan it to see if it's zero. That saves time in XLogInsert, and also allows reversion of my earlier patch to make PageRepairFragmentation et al explicitly re-zero freed space. Per suggestion by Heikki Linnakangas.
2005-06-06Remove the mostly-stubbed-out-anyway support routines for WAL UNDO.Tom Lane
That code is never going to be used in the foreseeable future, and where it's more than a stub it's making the redo routines harder to read.
2004-12-31Tag appropriate files for rc3PostgreSQL Daemon
Also performed an initial run through of upgrading our Copyright date to extend to 2005 ... first run here was very simple ... change everything where: grep 1996-2004 && the word 'Copyright' ... scanned through the generated list with 'less' first, and after, to make sure that I only picked up the right entries ...
2004-12-22Awhile back I added some code to StartupCLOG() to forcibly zero outTom Lane
the remainder of the current clog page during system startup. While this was a good idea, it turns out the code fails if nextXid is exactly at a page boundary, because we won't have created the "current" clog page yet in that case. Since the page will be correctly zeroed when we execute the first transaction on it, the solution is just to do nothing when exactly at a page boundary. Per trouble report from Dave Hartwig.
2004-08-30Ensure that the remainder of the current pg_clog page is zeroed duringTom Lane
startup, just to be sure that there's no leftover junk there.
2004-08-29Pgindent run for 8.0.Bruce Momjian
2004-08-29Update copyright to 2004.Bruce Momjian
2004-08-23Rearrange pg_subtrans handling as per recent discussion. pg_subtransTom Lane
updates are no longer WAL-logged nor even fsync'd; we do not need to, since after a crash no old pg_subtrans data is needed again. We truncate pg_subtrans to RecentGlobalXmin at each checkpoint. slru.c's API is refactored a little bit to separate out the necessary decisions.
2004-07-03Fix no-longer-correct bit-pushing in TransactionIdSetStatus, per Alvaro.Tom Lane
2004-07-01Nested transactions. There is still much left to do, especially on theTom Lane
performance front, but with feature freeze upon us I think it's time to drive a stake in the ground and say that this will be in 7.5. Alvaro Herrera, with some help from Tom Lane.
2004-05-31Per previous discussions, get rid of use of sync(2) in favor ofTom Lane
explicitly fsync'ing every (non-temp) file we have written since the last checkpoint. In the vast majority of cases, the burden of the fsyncs should fall on the bgwriter process not on backends. (To this end, we assume that an fsync issued by the bgwriter will force out blocks written to the same file by other processes using other file descriptors. Anyone have a problem with that?) This makes the world safe for WIN32, which ain't even got sync(2), and really makes the world safe for Unixen as well, because sync(2) never had the semantics we need: it offers no way to wait for the requested I/O to finish. Along the way, fix a bug I recently introduced in xlog recovery: file truncation replay failed to clear bufmgr buffers for the dropped blocks, which could result in 'PANIC: heap_delete_redo: no block' later on in xlog replay.
2003-11-29$Header: -> $PostgreSQL Changes ...PostgreSQL Daemon
2003-08-04Update copyrights to 2003.Bruce Momjian
2003-08-04pgindent run.Bruce Momjian
2003-06-11This patch extracts page buffer pooling and the simpleBruce Momjian
least-recently-used strategy from clog.c into slru.c. It doesn't change any visible behaviour and passes all regression tests plus a TruncateCLOG test done manually. Apart from refactoring I made a little change to SlruRecentlyUsed, formerly ClogRecentlyUsed: It now skips incrementing lru_counts, if slotno is already the LRU slot, thus saving a few CPU cycles. To make this work, lru_counts are initialised to 1 in SimpleLruInit. SimpleLru will be used by pg_subtrans (part of the nested transactions project), so the main purpose of this patch is to avoid future code duplication. Manfred Koizar
2003-05-03Handle clog structure in shared memory in exec() case, for Win32.Bruce Momjian
2003-05-02Back out last commit --- wrong patch.Bruce Momjian
2003-05-02Dump/read non-default GUC values for use by exec'ed backends, for Win32.Bruce Momjian
2003-04-14Reorganize clog's error reporting so that PANIC on clog I/O error canTom Lane
be reduced to a plain ERROR. Should make it at least a little less painful to deal with data-corruption problems.
2002-09-26Ensure that before truncating CLOG, we force a checkpoint even if noTom Lane
recent WAL activity has occurred. Without this, it's possible that a later crash might leave tuples on disk with un-updated commit status bits.
2002-09-02Remove sys/types.h in files that include postgres.h, and hence c.h,Bruce Momjian
because c.h has sys/types.h.
2002-06-20Update copyright to 2002.Bruce Momjian
2002-03-02Commit to match discussed elog() changes. Only update is that LOG isBruce Momjian
now just below FATAL in server_min_messages. Added more text to highlight ordering difference between it and client_min_messages. --------------------------------------------------------------------------- REALLYFATAL => PANIC STOP => PANIC New INFO level the prints to client by default New LOG level the prints to server log by default Cause VACUUM information to print only to the client NOTICE => INFO where purely information messages are sent DEBUG => LOG for purely server status messages DEBUG removed, kept as backward compatible DEBUG5, DEBUG4, DEBUG3, DEBUG2, DEBUG1 added DebugLvl removed in favor of new DEBUG[1-5] symbols New server_min_messages GUC parameter with values: DEBUG[5-1], INFO, NOTICE, ERROR, LOG, FATAL, PANIC New client_min_messages GUC parameter with values: DEBUG[5-1], LOG, INFO, NOTICE, ERROR, FATAL, PANIC Server startup now logged with LOG instead of DEBUG Remove debug_level GUC parameter elog() numbers now start at 10 Add test to print error message if older elog() values are passed to elog() Bootstrap mode now has a -d that requires an argument, like postmaster
2001-10-28Another pgindent run. Fixes enum indenting, and improves #endifBruce Momjian
spacing. Also adds space for one-line comments.
2001-10-25Fix a couple of places where lack of parenthesization of a castTom Lane
causes pgindent to make weird formatting decisions. Easiest fix seems to be to put in the extra parens...