PostgreSQL 9.1.13 commit log

commit   : 697becf743b3176a038d78857b14976d441a0027    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 17 Mar 2014 15:37:27 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 17 Mar 2014 15:37:27 -0400    

commit   : f0a8488ab74502fe376a4d542437b770299a3d79    
  
author   : Tom Lane <[email protected]>    
date     : Mon, 17 Mar 2014 15:28:32 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Mon, 17 Mar 2014 15:28:32 -0400    

commit   : 65e8dbb1869db542c93333fc809f34c7d3f7d9bd    
  
author   : Fujii Masao <[email protected]>    
date     : Mon, 17 Mar 2014 20:42:35 +0900    
  
committer: Fujii Masao <[email protected]>    
date     : Mon, 17 Mar 2014 20:42:35 +0900    

On clean shutdown, walsender waits for all WAL to be replicated to a standby,  
and exits. It determined whether that replication had been completed by  
checking whether its sent location had been equal to a standby's flush  
location. Unfortunately this condition never becomes true when the standby  
such as pg_receivexlog which always returns an invalid flush location is  
connecting to walsender, and then walsender waits forever.  
  
This commit changes walsender so that it just checks a standby's write  
location if a flush location is invalid.  
  
Back-patch to 9.1 where enough infrastructure for this exists.  

commit   : f84997c7e6687548d0d92631dceb125f89e55a2b    
  
author   : Alvaro Herrera <[email protected]>    
date     : Sun, 16 Mar 2014 23:22:22 -0300    
  
committer: Alvaro Herrera <[email protected]>    
date     : Sun, 16 Mar 2014 23:22:22 -0300    

Backpatch all the way back to 9.1, where it was introduced by commit  
50d89d42.  
  
Reported by Sergey Burladyan in #9223  
Author: Alex Hunsaker  

commit   : 8976360ea69389af5bc536abf1335a97c39c78b6    
  
author   : Peter Eisentraut <[email protected]>    
date     : Sun, 16 Mar 2014 21:38:55 -0400    
  
committer: Peter Eisentraut <[email protected]>    
date     : Sun, 16 Mar 2014 21:38:55 -0400    

commit   : 6b736102e40dd970037a21e756696f8e22bd8e61    
  
author   : Tom Lane <[email protected]>    
date     : Sun, 16 Mar 2014 21:43:49 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sun, 16 Mar 2014 21:43:49 -0400    

"8" was correct back when "disable" was the longest allowed value, but  
since "verify-full" was added, it should be "12".  Given the lack of  
complaints, I wouldn't be surprised if nobody is actually using these  
values ... but still, if they're in the API, they should be right.  
  
Noticed while pursuing a different problem.  It's been wrong for quite  
a long time, so back-patch to all supported branches.  

commit   : fae12f3310aa515fda9c7659d6ce9350176fb929    
  
author   : Magnus Hagander <[email protected]>    
date     : Sun, 16 Mar 2014 11:46:20 +0100    
  
committer: Magnus Hagander <[email protected]>    
date     : Sun, 16 Mar 2014 11:46:20 +0100    

This is a backpatch of 7f3e17b4827b61ad84e0774e3e43da4c57c4487f  
to 9.0 and 9.1.  
  
Patch by MauMau  

commit   : 2df1bf21c77537043e058a6d03c42f0e8423902c    
  
author   : Tom Lane <[email protected]>    
date     : Sat, 15 Mar 2014 13:36:07 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Sat, 15 Mar 2014 13:36:07 -0400    

DST law changes in Fiji, Turkey; historical changes in Israel, Ukraine.  

commit   : f16ca975500b7aab5026f164b1bc7bf833e2190b    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 13 Mar 2014 20:59:51 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 13 Mar 2014 20:59:51 -0400    

This should eliminate the risk of recursive entry to syslog(3), which  
appears to be the cause of the hang reported in bug #9551 from James  
Morton.  
  
Arguably, the real problem here is auth.c's willingness to turn on  
ImmediateInterruptOK while executing fairly wide swaths of backend code.  
We may well need to work at narrowing the code ranges in which the  
authentication_timeout interrupt is enabled.  For the moment, though,  
this is a cheap and reasonably noninvasive fix for a field-reported  
failure; the other approach would be complex and not necessarily  
bug-free itself.  
  
Back-patch to all supported branches.  

commit   : 7bfdf10f5aa33b9878a24d618dca75e9f60255d9    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 13 Mar 2014 12:03:03 -0400    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 13 Mar 2014 12:03:03 -0400    

Use TransactionIdIsInProgress, then TransactionIdDidCommit, to distinguish  
whether a NOTIFY message's originating transaction is in progress,  
committed, or aborted.  The previous coding could accept a message from a  
transaction that was still in-progress according to the PGPROC array;  
if the client were fast enough at starting a new transaction, it might fail  
to see table rows added/updated by the message-sending transaction.  Which  
of course would usually be the point of receiving the message.  We noted  
this type of race condition long ago in tqual.c, but async.c overlooked it.  
  
The race condition probably cannot occur unless there are multiple NOTIFY  
senders in action, since an individual backend doesn't send NOTIFY signals  
until well after it's done committing.  But if two senders commit in close  
succession, it's certainly possible that we could see the second sender's  
message within the race condition window while responding to the signal  
from the first one.  
  
Per bug #9557 from Marko Tiikkaja.  This patch is slightly more invasive  
than what he proposed, since it removes the now-redundant  
TransactionIdDidAbort call.  
  
Back-patch to 9.0, where the current NOTIFY implementation was introduced.  

commit   : 63e59c25961f14763d86a44d8e2eccafaa337d75    
  
author   : Heikki Linnakangas <[email protected]>    
date     : Wed, 12 Mar 2014 09:59:49 +0200    
  
committer: Heikki Linnakangas <[email protected]>    
date     : Wed, 12 Mar 2014 09:59:49 +0200    

We don't take a full-page image of the GIN metapage; instead, the WAL record  
contains all the information required to reconstruct it from scratch. But  
to avoid torn page hazards, we must re-initialize it from the WAL record  
every time, even if it already has a greater LSN, similar to how normal full  
page images are restored.  
  
This was highly unlikely to cause any problems in practice, because the GIN  
metapage is small. We rely on an update smaller than a 512 byte disk sector  
to be atomic elsewhere, at least in pg_control. But better safe than sorry,  
and this would be easy to overlook if more fields are added to the metapage  
so that it's no longer small.  
  
Reported by Noah Misch. Backpatch to all supported versions.  

commit   : 080ad9120d79933e5aed545986885058f8aa7385    
  
author   : Heikki Linnakangas <[email protected]>    
date     : Fri, 7 Mar 2014 13:25:11 +0200    
  
committer: Heikki Linnakangas <[email protected]>    
date     : Fri, 7 Mar 2014 13:25:11 +0200    

A fake relcache entry can "own" a SmgrRelation object, like a regular  
relcache entry. But when it was free'd, the owner field in SmgrRelation  
was not cleared, so it was left pointing to free'd memory.  
  
Amazingly this apparently hasn't caused crashes in practice, or we would've  
heard about it earlier. Andres found this with Valgrind.  
  
Report and fix by Andres Freund, with minor modifications by me. Backpatch  
to all supported versions.  

commit   : c7a186e392d4654148a45eaf8ffbf026553ecbdb    
  
author   : Heikki Linnakangas <[email protected]>    
date     : Fri, 7 Mar 2014 13:13:33 +0200    
  
committer: Heikki Linnakangas <[email protected]>    
date     : Fri, 7 Mar 2014 13:13:33 +0200    

The behavior of that is undefined, although unlikely to lead to problems in  
practice.  
  
Found by running regression tests with Valgrind.  

commit   : ff2e0e1f96ae412d06d0d10551161ca027d897fd    
  
author   : Heikki Linnakangas <[email protected]>    
date     : Fri, 7 Mar 2014 10:35:37 +0200    
  
committer: Heikki Linnakangas <[email protected]>    
date     : Fri, 7 Mar 2014 10:35:37 +0200    

Michael Paquier  

commit   : f3e3f6c5ba061ca8228649a5b9c0faa3d0ff4121    
  
author   : Tom Lane <[email protected]>    
date     : Thu, 6 Mar 2014 19:31:16 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Thu, 6 Mar 2014 19:31:16 -0500    

In make_ruledef and get_query_def, we have long used AcquireRewriteLocks  
to ensure that the querytree we are about to deparse is up-to-date and  
the schemas of the underlying relations aren't changing.  Howwever, that  
function thinks the query is about to be executed, so it acquires locks  
that are stronger than necessary for the purpose of deparsing.  Thus for  
example, if pg_dump asks to deparse a rule that includes "INSERT INTO t",  
we'd acquire RowExclusiveLock on t.  That results in interference with  
concurrent transactions that might for example ask for ShareLock on t.  
Since pg_dump is documented as being purely read-only, this is unexpected.  
(Worse, it used to actually be read-only; this behavior dates back only  
to 8.1, cf commit ba4200246.)  
  
Fix this by adding a parameter to AcquireRewriteLocks to tell it whether  
we want the "real" execution locks or only AccessShareLock.  
  
Report, diagnosis, and patch by Dean Rasheed.  Back-patch to all supported  
branches.  

commit   : 7552d3d1aba33198141f4953379f819df23988cf    
  
author   : Heikki Linnakangas <[email protected]>    
date     : Wed, 5 Mar 2014 13:27:18 +0200    
  
committer: Heikki Linnakangas <[email protected]>    
date     : Wed, 5 Mar 2014 13:27:18 +0200    

When entering crash recovery followed by archive recovery, and the latest  
checkpoint is a shutdown checkpoint, and there are no more WAL records to  
replay before transitioning from crash to archive recovery, we would not  
immediately allow read-only connections in hot standby mode even if we  
could. That's because when starting from a shutdown checkpoint, we set  
lastReplayedEndRecPtr incorrectly to the record before the checkpoint  
record, instead of the checkpoint record itself. We don't run the redo  
routine of the shutdown checkpoint record, but starting recovery from it  
goes through the same motions, so it should be considered as replayed.  
  
Reported by Kyotaro HORIGUCHI. All versions with hot standby are affected,  
so backpatch to 9.0.  

commit   : a9eb4924a581282abbb80b26396db08f9fb15f57    
  
author   : Tom Lane <[email protected]>    
date     : Sat, 1 Mar 2014 15:21:07 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Sat, 1 Mar 2014 15:21:07 -0500    

The regex code didn't have any provision for query cancel; which is  
unsurprising given its non-Postgres origin, but still problematic since  
some operations can take a long time.  Introduce a callback function to  
check for a pending query cancel or session termination request, and  
call it in a couple of strategic spots where we can make the regex code  
exit with an error indicator.  
  
If we ever actually split out the regex code as a standalone library,  
some additional work will be needed to let the cancel callback function  
be specified externally to the library.  But that's straightforward  
(certainly so by comparison to putting the locale-dependent character  
classification logic on a similar arms-length basis), and there seems  
no need to do it right now.  
  
A bigger issue is that there may be more places than these two where  
we need to check for cancels.  We can always add more checks later,  
now that the infrastructure is in place.  
  
Since there are known examples of not-terribly-long regexes that can  
lock up a backend for a long time, back-patch to all supported branches.  
I have hopes of fixing the known performance problems later, but adding  
query cancel ability seems like a good idea even if they were all fixed.  

commit   : 3e2db4c80bc631edfde57f8418551e2d5a79858f    
  
author   : Tom Lane <[email protected]>    
date     : Tue, 25 Feb 2014 16:04:16 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Tue, 25 Feb 2014 16:04:16 -0500    

If there are lots of uncommitted tuples at the end of the index range,  
get_actual_variable_range() ends up fetching each one and doing an MVCC  
visibility check on it, until it finally hits a visible tuple.  This is  
bad enough in isolation, considering that we don't need an exact answer  
only an approximate one.  But because the tuples are not yet committed,  
each visibility check does a TransactionIdIsInProgress() test, which  
involves scanning the ProcArray.  When multiple sessions do this  
concurrently, the ensuing contention results in horrid performance loss.  
20X overall throughput loss on not-too-complicated queries is easy to  
demonstrate in the back branches (though someone's made it noticeably  
less bad in HEAD).  
  
We can dodge the problem fairly effectively by using SnapshotDirty rather  
than a normal MVCC snapshot.  This will cause the index probe to take  
uncommitted tuples as good, so that we incur only one tuple fetch and test  
even if there are many such tuples.  The extent to which this degrades the  
estimate is debatable: it's possible the result is actually a more accurate  
prediction than before, if the endmost tuple has become committed by the  
time we actually execute the query being planned.  In any case, it's not  
very likely that it makes the estimate a lot worse.  
  
SnapshotDirty will still reject tuples that are known committed dead, so  
we won't give bogus answers if an invalid outlier has been deleted but not  
yet vacuumed from the index.  (Because btrees know how to mark such tuples  
dead in the index, we shouldn't have a big performance problem in the case  
that there are many of them at the end of the range.)  This consideration  
motivates not using SnapshotAny, which was also considered as a fix.  
  
Note: the back branches were using SnapshotNow instead of an MVCC snapshot,  
but the problem and solution are the same.  
  
Per performance complaints from Bartlomiej Romanski, Josh Berkus, and  
others.  Back-patch to 9.0, where the issue was introduced (by commit  
40608e7f949fb7e4025c0ddd5be01939adc79eec).  

commit   : e6f7fe983e1b454d4ec9e73a29be49ab3caaf409    
  
author   : Tom Lane <[email protected]>    
date     : Tue, 18 Feb 2014 12:44:30 -0500    
  
committer: Tom Lane <[email protected]>    
date     : Tue, 18 Feb 2014 12:44:30 -0500    

The SQL standard says that OVERLAPS should have a two-element row  
constructor on each side.  The original coding of OVERLAPS support in  
our grammar attempted to extend that by allowing a single-element row  
constructor, which it internally duplicated ... or tried to, anyway.  
But that code has certainly not worked since our List infrastructure was  
rewritten in 2004, and I'm none too sure it worked before that.  As it  
stands, it ends up building a List that includes itself, leading to  
assorted undesirable behaviors later in the parser.  
  
Even if it worked as intended, it'd be a bit evil because of the  
possibility of duplicate evaluation of a volatile function that the user  
had written only once.  Given the lack of documentation, test cases, or  
complaints, let's just get rid of the idea and only support the standard  
syntax.  
  
While we're at it, improve the error cursor positioning for the  
wrong-number-of-arguments errors, and inline the makeOverlaps() function  
since it's only called in one place anyway.  
  
Per bug #9227 from Joshua Yanovski.  Initial patch by Joshua Yanovski,  
extended a bit by me.  

commit   : 2eb60c52c1a7961b29b80143285d5a0249b8583f    
  
author   : Peter Eisentraut <[email protected]>    
date     : Mon, 17 Feb 2014 16:57:27 -0500    
  
committer: Peter Eisentraut <[email protected]>    
date     : Mon, 17 Feb 2014 16:57:27 -0500