== PostgreSQL Weekly News - May 02 2010 ==

== PostgreSQL Weekly News - May 02 2010 ==

PostgreSQL 9.0beta1 out soon. Get ready to test!
http://wiki.postgresql.org/wiki/HowToBetaTest

== PostgreSQL Product News ==

New PostgreSQL LiveCDs based on PostgreSQL 8.4 atop Fedora 12 and
CentOS 5.4 are out.
http://www.pglivecd.org/

PL/Proxy 2.1.0, a write-scaling clustering system for PostgreSQL, released.
http://pgfoundry.org/projects/plproxy/

== PostgreSQL 9.0 Feature of the Week ==

You can now call functions with named parameters, e.g.
foo('value' AS parameter_foo, 'other value' AS parameter_bar)

== PostgreSQL Local ==

Andreas (ads) Scherbaum will be teaching a "PostgreSQL for Corporate
Use" course at the adult education center in Magdeburg, Germany May
3-7, 2010. Details below:
http://andreas.scherbaum.la/blog/archives/650-PostgreSQL-Schulung-als-Bildungsurlaub-03.-07.05.2010-in-Magdeburg.html

PgCon 2010 will be held May 20-21 2010 in Ottawa with tutorials before
on the 18th and 19th.
http://www.pgcon.org/2010/registration.php

Registration for Open Source Bridge is open and talks are announced!
June 1-4, 2010 in Portland, Oregon.
http://opensourcebridge.org/events/2010/proposals/

Michael Renner will be speaking at AMOOCON, which goes from June 4-6, 2010.
http://www.amoocon.de/speakers/214

Southeast Linuxfest 2010 will take place in Spartanburg, SC, USA on
June 12-13.  Booths and sponsorships are still available.
http://southeastlinuxfest.org/

OSCON will take place in Portland, Oregon July 19-23, 2010.
http://www.oscon.com/oscon2010

== 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(at)fetter(dot)org, German language
to pwn(at)pgug(dot)de, Italian language to pwn(at)itpug(dot)org(dot) Spanish language
to pwn(at)arpug(dot)com(dot)ar(dot)

== Applied Patches ==

Robert Haas committed:

- When we're restricting who can connect, don't allow new walsenders.
Normal superuser processes are allowed to connect even when the
database system is shutting down, or when fewer than
superuser_reserved_connection slots remain. This is intended to
make sure an administrator can log in and troubleshoot, so don't
extend these same courtesies to users connecting for replication.

Bruce Momjian committed:

- In pgsql/src/backend/utils/adt/pg_locale.c, add comments about why
we set LC_CTYPE in WIN32 for time when we don't actually access it,
per information from Hiroshi Inoue.

- Reorder pg_stat_activity columns to be more consistent, using layout
suggested by Tom Lane. Catalog version bumped due to system view
change.

- In pgsql/doc/src/sgml/high-availability.sgml, document that pgpool
can be used with master/slave servers to avoid problems with
non-deterministic functions.

- In pgsql/doc/src/sgml/release-9.0.sgml, update 9.0 release notes to
current; add major items and introductory text.

- Move alpha release notes into a separate file; re-align sgml tags.

- In pgsql/doc/src/sgml/release-9.0.sgml, doc fix -- last major item
should not be a bullet.

- In pgsql/doc/src/sgml/release-9.0.sgml, documentation fix: CREATE
TRIGGER 'WHERE' -> 'WHEN'. Selena Deckelmann.

Tom Lane committed:

- In pgsql/src/backend/tsearch/wparser_def.c, add missing newlines in
WPARSER_TRACE output.

- In pgsql/doc/src/sgml/monitoring.sgml, update documentation to match
pg_stat_activity changes.

- Replace the KnownAssignedXids hash table with a sorted-array data
structure, and be more tense about the locking requirements for it,
to improve performance in Hot Standby mode. In passing fix a few
bugs and improve a number of comments in the existing Hot Standby
code. Simon Riggs, with some editorialization by Tom Lane.

- In pgsql/src/backend/parser/parse_relation.c, fix stupid typo in
refnameRangeTblEntry() --- mea maxima culpa. Per report from Josh
Berkus.

- Modify the built-in text search parser to handle URLs more nearly
according to RFC 3986. In particular, these characters now
terminate the path part of a URL: '"', '<', '>', '\', '^', '`', '{',
'|', '}'. The previous behavior was inconsistent and depended on
whether a "?" was present in the path. Per gripe from Donald Fraser
and spec research by Kevin Grittner. This is a pre-existing bug,
but not back-patching since the risks of breaking existing
applications seem to outweigh the benefits.

- Fix contrib/tsearch2 expected results to match recent changes in URL
parsing.

- Modify ShmemInitStruct and ShmemInitHash to throw errors internally,
rather than returning NULL for some-but-not-all failures as they
used to. Remove now-redundant tests for NULL from call sites. We
had to do something about this because many call sites were failing
to check for NULL; and changing it like this seems a lot more useful
and mistake-proof than adding checks to the call sites without them.

- In pgsql/src/bin/pg_controldata/pg_controldata.c, pg_controldata
needs #define FRONTEND, same as pg_resetxlog. Per buildfarm results
from dawn_bat.

- Minor editorializing on pg_controldata and pg_resetxlog: adjust some
message wording, deal explicitly with some fields that were being
silently left zero.

- In pgsql/src/backend/catalog/information_schema.sql, modify
information_schema._pg_keysequal() to avoid search path risk when
contrib/intarray is loaded. Per bug #5417 from Kenaniah Cerny. Not
forcing initdb since backend doesn't directly depend on this, and
few people have run into it.

- In pgsql/doc/src/sgml/perform.sgml, fix typo, per Thom Brown.

- In pgsql/doc/src/sgml/jadetex.cfg, install a workaround for 'TeX
capacity exceeded' problem when building PDF output for recent
versions of the documentation. There is probably a better answer
out there somewhere, but we need something now so we can build beta
releases.

- Rename the parameter recovery_connections to hot_standby, to reduce
possible confusion with streaming-replication settings. Also,
change its default value to "off", because of concern about
executing new and poorly-tested code during ordinary non-replicating
operation. Per discussion. In passing do some minor editing of
related documentation.

- Adjust error checks in pg_start_backup and pg_stop_backup to make it
possible to perform a backup without archive_mode being enabled.
This gives up some user-error protection in order to improve
usefulness for streaming-replication scenarios. Per discussion.

- Fix a couple of places where the result of fgets() wasn't checked.
This is mostly to suppress compiler warnings, although in principle
the cases could result in undesirable behavior. Martin Pitt.

- In pgsql/src/pl/plpython/plpython.c, fix multiple memory leaks in
PLy_spi_execute_fetch_result: it would leak memory if the result had
zero rows, and also if there was any sort of error while converting
the result tuples into Python data. Reported and partially fixed by
Andres Freund. Back-patch to all supported versions. Note: I
haven't tested the 7.4 fix. 7.4's configure check for python is so
obsolete it doesn't work on my current machines :-(. The logic
change is pretty straightforward though.

- In pgsql/doc/src/sgml/ref/copy.sgml, improve COPY documentation to
clarify that it doesn't copy data to or from child tables. Per
gripe from Jaime Casanova.

- In pgsql/doc/src/sgml/runtime.sgml, update our information about OS
X shared memory configuration: it's now possible to set most of the
SHM kernel parameters without a reboot. Also, reorder the paragraph
to explain the modern configuration method first. There are
probably not too many people who still care about how to do it on OS
X 10.3 or older.

- In pgsql/src/pl/plpython/plpython.c, fix leakage of proc-related
storage in plpython's inline handler. Per report from Andres
Freund.

- In pgsql/doc/src/sgml/Makefile, adjust postgres.xml rule so that
make will notice a failure exit from osx. The previous coding had
it in a pipe, which on most shells won't report the error. Per
experimentation with a bug report from Vladimir Kokovic. This
doesn't actually fix his problem, but it does explain why make
didn't report that there was a problem.

- In pgsql/doc/src/sgml/Makefile, install hack workaround for failure
of 'make all' in VPATH builds. It appears that gmake gets confused
if postgres.sgml is not present in the working directory, and
instantiates some default rule or other that would let postgres.sgml
be built from postgres.xml. I haven't been able to track down
exactly where that's coming from, but the problem can be dodged by
specifying srcdir explicitly in the rule for postgres.xml. Per
report from Vladimir Kokovic.

- In pgsql/src/backend/port/sysv_shmem.c, add code to
InternalIpcMemoryCreate() to handle the case where shmget() returns
EINVAL for an existing shared memory segment. Although it's not
terribly sensible, that behavior does meet the POSIX spec because
EINVAL is the appropriate error code when the existing segment is
smaller than the requested size, and the spec explicitly disclaims
any particular ordering of error checks. Moreover, it does in fact
happen on OS X and probably other BSD-derived kernels. (We were
able to talk NetBSD into changing their code, but purging that
behavior from the wild completely seems unlikely to happen.) We need
to distinguish collision with a pre-existing segment from invalid
size request in order to behave sensibly, so it's worth some extra
code here to get it right. Per report from Gavin Kistner and
subsequent investigation. Back-patch to all supported versions,
since any of them could get used with a kernel having the debatable
behavior.

- Clean up some awkward, inaccurate, and inefficient processing around
MaxStandbyDelay. Use the GUC units mechanism for the value, and
choose more appropriate timestamp functions for performing tests
with it. Make the ps_activity manipulation in
ResolveRecoveryConflictWithVirtualXIDs have behavior similar to
ps_activity code elsewhere, notably not updating the display when
update_process_title is off and not truncating the display contents
at an arbitrarily-chosen length. Improve the docs to be explicit
about what MaxStandbyDelay actually measures, viz the difference
between primary and standby servers' clocks, and the possible
hazards if their clocks aren't in sync.

- In pgsql/src/backend/access/heap/heapam.c, fix replay of
XLOG_HEAP_NEWPAGE WAL records to pay attention to the forknum field
of the WAL record. The previous coding always wrote to the main
fork, resulting in data corruption if the page was meant to go into
a non-default fork. At present, the only operation that can produce
such WAL records is ALTER TABLE/INDEX SET TABLESPACE when executed
with archive_mode = on. Data corruption would be observed on
standby slaves, and could occur on the master as well if a database
crash and recovery occurred after committing the ALTER and before
the next checkpoint. Per report from Gordon Shannon. Back-patch to
8.4; the problem doesn't exist in earlier branches because we didn't
have a concept of multiple relation forks then.

- In pgsql/src/backend/access/heap/heapam.c, improve printing of
XLOG_HEAP_NEWPAGE records to include the forknum.

Heikki Linnakangas committed:

- In pgsql/src/backend/access/transam/xlog.c, if a base backup is
cancelled by server shutdown or crash, throw an error in WAL
recovery when it sees the shutdown checkpoint record. It's more
user-friendly to find out about it at that point than at the end of
recovery, and you're not left wondering why your hot standby server
never opens up for read-only connections.

- In pgsql/doc/src/sgml/recovery-config.sgml, add recovery.conf
parameters to the documentation index, per suggestion by Fujii
Masao.

- Introduce wal_level GUC to explicitly control if information needed
for archival or hot standby should be WAL-logged, instead of
deducing that from other options like archive_mode. This replaces
recovery_connections GUC in the primary, where it now has no effect,
but it's still used in the standby to enable/disable hot standby.
Remove the WAL-logging of "unlogged operations", like creating an
index without WAL-logging and fsyncing it at the end. Instead, we
keep a copy of the wal_mode setting and the settings that affect how
much shared memory a hot standby server needs to track master
transactions (max_connections, max_prepared_xacts,
max_locks_per_xact) in pg_control. Whenever the settings change, at
server restart, write a WAL record noting the new settings and
update pg_control. This allows us to notice the change in those
settings in the standby at the right moment, they used to be
included in checkpoint records, but that meant that a changed value
was not reflected in the standby until the first checkpoint after
the change. Bump PG_CONTROL_VERSION and XLOG_PAGE_MAGIC. Whack
XLOG_PAGE_MAGIC back to the sequence it used to follow, before hot
standby and subsequent patches changed it to 0x9003.

- In pgsql/src/backend/access/nbtree/nbtxlog.c, fix handling of b-tree
reuse WAL records when hot standby is disabled, and add missing code
in btree_desc for them. This fixes the bug with "tree_redo: unknown
op code 208" error reported by Jaime Casanova.

Alvaro Herrera committed:

- In pgsql/doc/src/sgml/plpgsql.sgml, reformat code examples in
plpgsql docs for better readability in PDF output. Erik Rijkers

- In pgsql/doc/src/sgml/perform.sgml, make pg_stats example query
result a bit less wide, and add comment about pg_stats.inherited

ITAGAKI Takahiro committed:

- In pgsql/src/port/chklocale.c, add CP949 as an alias for UHC
encoding. pg_get_encoding_from_locale() with kor locale on Windows
can use the path. Reported by Hiroshi Inoue.

Magnus Hagander committed:

- In pgsql/src/interfaces/libpq/fe-protocol3.c, fix typo that had the
code check the same thing twice. Fujii Masao.

Marc Fournier committed:

- Tag for 9.0beta1.

Simon Riggs committed:

- In pgsql/doc/src/sgml/config.sgml, mention that max_standby_delay
has units of milliseconds. Units are mentioned for all other
parameters where the default is expressed in a different unit.

- In pgsql/doc/src/sgml/regress.sgml, docs for standbycheck regression
tests.

- Update standbycheck test output with new ERROR message changes. No
changes to tests and no changes in accepted server behaviour.

== Rejected Patches (for now) ==

No one was disappointed this week :-)

== Pending Patches ==

Marko (johto) Tiikkaja sent in a patch to throw a more informative
warning when people use extra parentheses in INSERT statements.

Simon Riggs sent in another revision of the patch to fix the issue
where queries on the Hot Standby slave ran much slower than the same
queries on the master.

Heikki Linnakangas sent in a patch to relax the checks in
pg_start/stop_backup() so they can be used as long as wal_level >=
'archive', even when archiving is disabled.

Simon Riggs sent in a patch intended to improve the performance of
btree_xlog_vacuum().

Zoltan Boszormenyi sent in two revisions of a patch intended for 9.1
which adds synchronous replication atop Hot Standby/Streaming
Replication.

Aftab Hussain sent in a patch to add PKST (Pakstan Summer Time) to the
time zone list.

Robert Haas sent in a patch to implement CINE (Create If Not Exists)
for tables.

Greg Sabino Mullane sent in a patch to show the schema along with the
table involved in a COPY error.