== PostgreSQL Weekly News – May 20 2012 ==

== PostgreSQL Weekly News – May 20 2012 ==

The Call for Papers for PG.EU has begun. It will cover
topics for PostgreSQL users, developers and contributors, as well as
decision and policy makers. Talks should be in English or Czech.

== PostgreSQL Product News ==

pgAdmin v1.16.0 Beta 1 is now available for testing in source from:

PGXN Client 1.0.3 released.

== PostgreSQL Jobs for May ==


== PostgreSQL Local ==

PGDay France will be in Lyon on June 7, 2012.

PostgreSQL conference China 2012 will be on June 14-17, 2012 in Beijing.

PostgreSQL Session will be held on October 4th, 2012, in Paris,
France. More information at:

PostgreSQL Conference Europe 2012 will be in Prague, Czech Republic
on October 23-26. The call for sponsors is open.

== PostgreSQL in the News ==

Planet PostgreSQL: http://planet.postgresql.org/

PostgreSQL Weekly News is brought to you this week by David Fetter

Submit news and announcements by Sunday at 3:00pm Pacific time.
Please send English language ones to david@fetter.org, German language
to pwn@pgug.de, Italian language to pwn@itpug.org. Spanish language
to pwn@arpug.com.ar.

== Reviews ==

== Applied Patches ==

Heikki Linnakangas pushed:

- Update comments that became out-of-date with the PGXACT struct.
When the “hot” members of PGPROC were split off to separate PGXACT
structs, many PGPROC fields referred to in comments were moved to
PGXACT, but the comments were neglected in the commit. Mostly this
is just a search/replace of PGPROC with PGXACT, but the way the
dummy PGPROC entries are created for prepared transactions changed
more, making some of the comments totally bogus. Noah Misch

- Remove unnecessary pg_verifymbstr() calls from tsvector/query in
functions. The input should’ve been validated well before it hits
the input function. Doing so again is a waste of cycles.

- Fix bug in to_tsquery(). We were using memcpy() to copy to a
possibly overlapping memory region, which is a no-no. Use memmove()

- Fix bug in freespace calculation in heap_multi_insert(). If the
amount of freespace on page was less than the amount reserved by
fillfactor, the calculation would underflow. This fixes bug #6643
reported by Tomonari Katsumata.

- Fix bug in gistRelocateBuildBuffersOnSplit(). When we create a
temporary copy of the old node buffer, in stack, we mustn’t leak
that into any of the long-lived data structures. Before this patch,
when we called gistPopItupFromNodeBuffer(), it got added to the
array of “loaded buffers”. After gistRelocateBuildBuffersOnSplit()
exits, the pointer added to the loaded buffers array points to
garbage. Often that goes unnotied, because when we go through the
array of loaded buffers to unload them, buffers with a NULL
pageBuffer are ignored, which can often happen by accident even if
the pointer points to garbage. This patch fixes that by marking the
temporary copy in stack explicitly as temporary, and refrain from
adding buffers marked as temporary to the array of loaded buffers.
While we’re at it, initialize nodeBuffer->pageBlocknum to
InvalidBlockNumber and improve comments a bit. This isn’t strictly
necessary, but makes debugging easier.

Tom Lane pushed:

- Force pgwin32_recv into nonblock mode when called from pgstat.c.
This should get rid of the usage of pgwin32_waitforsinglesocket
entirely, and perhaps thereby remove the race condition that’s
evidently still present on some versions of Windows. The previous
arrangement was a bit unsafe anyway, since waiting at the recv()
would not allow pgstat to notice postmaster death.

- For testing purposes, reinsert a timeout in pgstat.c’s wait call.
Test results from buildfarm members mastodon/narwhal (Windows Server
2003) make it look like that platform just plain loses FD_READ
events occasionally, and the only reason our previous coding seemed
to work was that it timed out every couple of seconds and retried
the whole operation. Try to verify this by reinserting a finite
timeout into the pgstat loop. This isn’t meant to be a permanent
patch either, just to confirm or disprove a theory.

- Assert that WaitLatchOrSocket callers cannot wait only for
writability. Since we have chosen to report socket EOF and error
conditions via the WL_SOCKET_READABLE flag bit, it’s unsafe to wait
only for WL_SOCKET_WRITEABLE; the caller would never be notified of
the socket condition, and in some of these implementations
WaitLatchOrSocket would busy-wait until something else happens. Add
this restriction to the API specification, and add Asserts to check
that callers don’t try to do that. At some point we might want to
consider adjusting the API to relax this restriction, but until we
have an actual use case for waiting on a write-only socket, it seems
premature to design a solution.

- Put back AC_REQUIRE([AC_STRUCT_TM]). The BSD-ish members of the
buildfarm all seem to think removing this was a bad idea. It looks
to me like it resulted in omitting the system header inclusion
necessary to detect the fields of struct tm correctly.

- Revert “Add some temporary instrumentation to pgstat.c.” This
reverts commit 7d88bb73f755f7fb5d847ef2319c21076054fb0e. That
instrumentation has served its purpose.

- In pgstat.c, use a timeout in WaitLatchOrSocket only on Windows. We
have no need for a timeout here really, but some broken products
from Redmond seem to lose FD_READ events occasionally, and waking up
and retrying the recv() is the only known way to work around that.
Perhaps somebody will be motivated to figure out a better answer
here; but not I.

- Improve error message for ALTER COLUMN TYPE coercion failure. Per
recent discussion, the error message for this was actually a trifle
inaccurate, since it said “cannot be cast” which might be incorrect.
Adjust that wording, and add a HINT suggesting that a USING clause
might be needed.

Peter Eisentraut pushed:

- Remove unused AC_DEFINE symbols: ENABLE_DTRACE unused as of
a7b7b07af340c73adee9959edf260695591a9496, HAVE_ERR_SET_MARK unused
as of 4ed4b6c54e5fab24ab2624d80e26f7546edc88ad, HAVE_FCVT unused as
of 4553e1d80f824291932cfde30aa24a76dd8f1941, HAVE_STRUCT_SOCKADDR_UN
unused as of b4cea00a1fc9d2270bfe9aeeee44915378d5f733, HAVE_SYSCONF
unused as of f83356c7f574bc69969f29dc7b430b286a0cd9f4,
TM_IN_SYS_TIME never used, obsolescent per Autoconf documentation,

- Remove stray nbsp character

- Make xrefs to tables instead of assuming they appear below

- Remove whitespace from end of lines. pgindent and perltidy should
clean up the rest.

- Fix a whitespace issue with the man pages. See
6ef24487967692604b07a4a54e71821a60fb729a for an explanation. This
is the same for the new man pages.

- Change COLLATION keyword category. It was changed from unreserved
to reserved as part of the COLLATION FOR syntax, but it turns out
that type_func_name_keyword is sufficient.

- Update SQL features/conformance information to SQL:2011

- Update key words table for 9.2

- file_fdw: Improve error message. The hint looked a bit confusing
when there were no valid options to hint about.

- Realign some –help output to have better spacing between columns

- Put back word that was mysteriously lost in man page conversion

- Fix incorrect logic in JSON number lexer. Detectable by gcc
-Wlogical-op. Add two regression test cases that would previously
allow incorrect values to pass.

- Small cleanups of contrib –help output

- Some reference page improvements. initdb: Add -T option. oid2name:
Put options in some non-random order. pg_dump: Put –section option
in the right place. And some additional markup and terminology

Michael Meskes pushed:

- Reworded sentence as suggested by Stephen Frost.

== Rejected Patches (for now) ==

No one was disappointed this week

== Pending Patches ==

Gilles Darold sent in another revision of the patch to add
pg_is_in_backup() and pg_backup_start_time().

Fujii Masao sent in a patch which moves the existing calls of
WalSndWakeup() out of a critical section and adds new call of
WalSndWakeup() to XLogBackgroundFlush().

Alexander Shulgin sent in another revision of the patch to make libpq
understand an RFC compliant URI connection string for PostgreSQL.

Kyotaro HORIGUCHI sent in a patch to fix an infelicity in checkpointer.

Stephen Frost sent in another revision of a patch to speed up some
operations by pre-allocating ListCells.

Robert Haas sent in a patch which provides some rough instrumentation
for determining where palloc calls are coming from.

Peter Eisentraut sent in a patch to add an aclcheck_error_type()

Comments are closed.