== PostgreSQL Weekly News - April 08 2012 == - Mailing list pgsql-announce

== PostgreSQL Weekly News - April 08 2012 ==

== PostgreSQL Product News ==

LuaPgSQL, a Lua binding for PostgreSQL, released:
https://github.com/mbalmer/luapgsql

== PostgreSQL Jobs for April ==

http://archives.postgresql.org/pgsql-jobs/2012-04/threads.php

== PostgreSQL Local ==

London PostgreSQL Evening Meetup, 17 April 2012
http://www.meetup.com/London-PostgreSQL-Meetup-Group/

PGCon 2012 will be held 17-18 May 2012, in Ottawa at the University of
Ottawa.  It will be preceded by two days of tutorials on 15-16 May 2012.
http://www.pgcon.org/2012/

PGDay France will be in Lyon on June 7, 2012.
http://www.pgday.fr

== 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.

== Applied Patches ==

Peter Eisentraut pushed:

- Add support for renaming domain constraints
  http://git.postgresql.org/pg/commitdiff/38b9693fd9847f4dcf6ff2fc469a7f2aac6385d9

- NLS: Use msgmerge/xgettext --no-wrap and --sort-by-file.  The option
  --no-wrap prevents wars with (most?) editors about proper line
  wrapping.  --sort-by-file ensures consistent file order, for easier
  diffing.
  http://git.postgresql.org/pg/commitdiff/05261ab6246cba9701b8529eba812b8a68c3be8d

- Correct various system catalog/view definitions in the
  documentation.  Thom Brown
  http://git.postgresql.org/pg/commitdiff/25028a27c828b8d31a85064f230113a42c0fea81

- Fix some typos in the documentation.  Thom Brown
  http://git.postgresql.org/pg/commitdiff/6c41948c39288139cd9a592466cd373b6868bb55

Robert Haas pushed:

- Arrange for on_exit_nicely to be thread-safe.  Extracted from
  Joachim Wieland's parallel pg_dump patch, with some additional
  comments by me.
  http://git.postgresql.org/pg/commitdiff/5e86c61a7eec0fdc6961493a150159fa8fc63b1c

- Expose track_iotiming data via the statistics collector.  Ants
  Aasma's original patch to add timing information for buffer I/O
  requests exposed this data at the relation level, which was judged
  too costly.  I've here exposed it at the database level instead.
  http://git.postgresql.org/pg/commitdiff/644828908fb132ee1f1da5b8b7975c0d73d6158a

- Correctly explain units used by function-timing stats functions.
  The views are in milliseconds, but the raw functions return
  microseconds.
  http://git.postgresql.org/pg/commitdiff/97e26dc66d47624bdbdee1dbd007a0f4212defcb

- Publish checkpoint timing information to pg_stat_bgwriter.  Greg
  Smith, Peter Geoghegan, and Robert Haas
  http://git.postgresql.org/pg/commitdiff/b736aef2ec57b520ebadb70cceac0fed3168a5df

- Allow pg_archivecleanup to strip optional file extensions.  Greg
  Smith and Jaime Casanova, reviewed by Alex Shulgin and myself.
  http://git.postgresql.org/pg/commitdiff/bbc02243fcf2fbf51b6bacf05a73fa042d3d84a4

- checkopint -> checkpoint.  Report by Guillaume Lelarge.
  http://git.postgresql.org/pg/commitdiff/21cc529698c8d10c6f7c76874d4adc98d27c6187

- Put back code inadvertently deleted from exit_nicely.  Report by
  Andrew Dunstan.
  http://git.postgresql.org/pg/commitdiff/662ca285a6f8fee5616eb2770f889ee94a040afa

- Teach SLRU code to avoid replacing I/O-busy pages.  Patch by me;
  review by Tom Lane and others.
  http://git.postgresql.org/pg/commitdiff/3ae5133b1cf478d516666f2003bc68ba0edb84c7

Tom Lane pushed:

- Fix a couple of contrib/dblink bugs.  dblink_exec leaked temporary
  database connections if any error occurred after connection setup,
  for example SELECT dblink_exec('...connect string...', 'select
  1/0'); Add a PG_TRY block to ensure PQfinish gets done when it is
  needed.  (dblink_record_internal is on the hairy edge of needing
  similar treatment, but seems not to be actively broken at the
  moment.) Also, in 9.0 and up, only one of the three functions using
  tuplestore return mode was properly checking that the query context
  would allow a tuplestore result.  Noted while reviewing dblink
  patch.  Back-patch to all supported branches.
  http://git.postgresql.org/pg/commitdiff/d843ed21164275dfbfefa486bb00bca91380cdf0

- Fix syslogger to not lose log coherency under high load.  The
  original coding of the syslogger had an arbitrary limit of 20 large
  messages concurrently in progress, after which it would just punt
  and dump message fragments to the output file separately.  Our
  ambitions are a bit higher than that now, so allow the data
  structure to expand as necessary.  Reported and patched by Andrew
  Dunstan; some editing by Tom
  http://git.postgresql.org/pg/commitdiff/c17e863bc7677a54d6da5bbb2868cca2cd9b30c1

- Remove useless PGRES_COPY_BOTH "support" in psql.  There is no
  existing or foreseeable case in which psql should see a
  PGRES_COPY_BOTH PQresultStatus; and if such a case ever emerges,
  it's a pretty good bet that these code fragments wouldn't do the
  right thing anyway.  Remove them, and let the existing default cases
  do the appropriate thing, namely emit an "unexpected PQresultStatus"
  bleat.  Noted while working on libpq row processor patch, for which
  I was considering adding a PGRES_SUSPENDED status code --- the same
  default-case treatment would be appropriate for that.
  http://git.postgresql.org/pg/commitdiff/cb917e1544612c187c74fed1a990e26820514c8a

- Add a "row processor" API to libpq for better handling of large
  results.  Traditionally libpq has collected an entire query result
  before passing it back to the application.  That provides a simple
  and transactional API, but it's pretty inefficient for large result
  sets.  This patch allows the application to process each row
  on-the-fly instead of accumulating the rows into the PGresult.
  Error recovery becomes a bit more complex, but often that tradeoff
  is well worth making.  Kyotaro Horiguchi, reviewed by Marko Kreen
  and Tom Lane
  http://git.postgresql.org/pg/commitdiff/92785dac2ee7026948962cd61c4cd84a2d052772

- Improve efficiency of dblink by using libpq's new row processor API.
  This patch provides a test case for libpq's row processor API.
  contrib/dblink can deal with very large result sets by dumping them
  into a tuplestore (which can spill to disk) --- but until now, the
  intermediate storage of the query result in a PGresult meant memory
  bloat for any large result.  Now we use a row processor to convert
  the data to tuple form and dump it directly into the tuplestore.  A
  limitation is that this only works for plain dblink() queries, not
  dblink_send_query() followed by dblink_get_result().  In the latter
  case we don't know the desired tuple rowtype soon enough.  While
  hack solutions to that are possible, a different user-level API
  would probably be a better answer.  Kyotaro Horiguchi, reviewed by
  Marko Kreen and Tom Lane
  http://git.postgresql.org/pg/commitdiff/6f922ef88e43b3084cdddf4b5ffe525a00896a90

- Fix plpgsql named-cursor-parameter feature for variable name
  conflicts.  The parser got confused if a cursor parameter had the
  same name as a plpgsql variable.  Reported and diagnosed by Yeb
  Havinga, though this isn't exactly his proposed fix.  Also, some
  mostly-but-not-entirely-cosmetic adjustments to the original
  named-cursor-parameter patch, for code readability and better error
  diagnostics.
  http://git.postgresql.org/pg/commitdiff/05dbd4a7734e09bd1f835f4197d9befa1c00c4f3

- Update obsolete comment.  Somebody didn't bother to fix this comment
  while adding foreign table support to the code below it.  In
  passing, remove the explicit calling-out of relkind letters, which
  adds complexity to the comment but doesn't help in understanding the
  code.
  http://git.postgresql.org/pg/commitdiff/a75b08066ab4b426b1bd056fed81302e5a5d5371

- Allow statistics to be collected for foreign tables.  ANALYZE now
  accepts foreign tables and allows the table's FDW to control how the
  sample rows are collected.  (But only manual ANALYZEs will touch
  foreign tables, for the moment, since among other things it's not
  very clear how to handle remote permissions checks in an
  auto-analyze.) contrib/file_fdw is extended to support this.  Etsuro
  Fujita, reviewed by Shigeru Hanada, some further tweaking by me.
  http://git.postgresql.org/pg/commitdiff/263d9de66b867b7800fac82c222e004b795b724a

- Dept of second thoughts: improve the API for AnalyzeForeignTable.
  If we make the initially-called function return the table
  physical-size estimate, acquire_inherited_sample_rows will be able
  to use that to allocate numbers of samples among child tables, when
  the day comes that we want to support foreign tables in inheritance
  trees.
  http://git.postgresql.org/pg/commitdiff/cea49fe82fedcf125eb99a780099eaf47a326b03

- Fix broken comparetup_datum code.  Commit
  337b6f5ecf05b21b5e997986884d097d60e4e3d0 contained the entirely
  fanciful assumption that it had made comparetup_datum unreachable.
  Reported and patched by Takashi Yamamoto.  Fix up some not terribly
  accurate/useful comments from that commit, too.
  http://git.postgresql.org/pg/commitdiff/17b985b1a068e120feb05bb61be6328f4fef8090

- Fix misleading output from gin_desc().  XLOG_GIN_UPDATE_META_PAGE
  and XLOG_GIN_DELETE_LISTPAGE records were printed with a list link
  field labeled as "blkno", which was confusing, especially when the
  link was empty (InvalidBlockNumber).  Print the metapage block
  number instead, since that's what's actually being updated.  We
  could include the link values too as a separate field, but not clear
  it's worth the trouble.  Back-patch to 8.4 where the dubious code
  was added.
  http://git.postgresql.org/pg/commitdiff/0ab4db52c0d45763adee3981da4325e7c353e443

- Update URL for pgtclng project.  Thom Brown
  http://git.postgresql.org/pg/commitdiff/d75829a682fdf832fe9d044b28be597d3f058ec8

- Remove useless variable to suppress compiler warning.
  http://git.postgresql.org/pg/commitdiff/a25ef7a5f68728f7f78f798a98c26b773c45937e

- Further adjustment of comment about qsort_tuple.
  http://git.postgresql.org/pg/commitdiff/95b9c333b25463283ba07c5ba7dbe79b4e8b4480

- Fix incorrect make maintainer-clean rule.
  http://git.postgresql.org/pg/commitdiff/7feecedccef078bb9f39188db2f75c1481b45cc3

- Improve management of "sticky" entries in
  contrib/pg_stat_statements.  This patch addresses a deficiency in
  the previous pg_stat_statements patch.  We want to give sticky
  entries an initial "usage" factor high enough that they probably
  will stick around until their query is completed.  However, if the
  query never completes (eg it gets an error during execution), the
  entry shouldn't persist indefinitely.  Manage this by starting out
  with a usage setting equal to the (approximate) median usage value
  within the whole hashtable, but decaying the value much more
  aggressively than we do for normal entries.  Peter Geoghegan
  http://git.postgresql.org/pg/commitdiff/d5375491f8e391224b48e4bb449995a4642183ea

Simon Riggs pushed:

- Add DROP INDEX CONCURRENTLY [IF EXISTS], uses ShareUpdateExclusiveLock
  http://git.postgresql.org/pg/commitdiff/8cb53654dbdb4c386369eb988062d0bbb6de725e

Bruce Momjian pushed:

- Stamp libraries versions for 9.2 (better late than never).
  http://git.postgresql.org/pg/commitdiff/d24ac36f4fb99824425c81a64a5e36f3e91a7656

Heikki Linnakangas pushed:

- Do stack-depth checking in all postmaster children.  We used to only
  initialize the stack base pointer when starting up a regular
  backend, not in other processes. In particular, autovacuum workers
  can run arbitrary user code, and without stack-depth checking,
  infinite recursion in e.g an index expression will bring down the
  whole cluster.  The comment about PL/Java using set_stack_base() is
  not yet true. As the code stands, PL/java still modifies the
  stack_base_ptr variable directly.  However, it's been discussed in
  the PL/Java mailing list that it should be changed to use the
  function, because PL/Java is currently oblivious to the register
  stack used on Itanium. There's another issues with PL/Java, namely
  that the stack base pointer it sets is not really the base of the
  stack, it could be something close to the bottom of the stack.
  That's a separate issue that might need some further changes to this
  code, but that's a different story.  Backpatch to all supported
  releases.
  http://git.postgresql.org/pg/commitdiff/ef3883d130cb553003015f3da7fa59415da6f5c9

- set_stack_base() no longer needs to be called in PostgresMain.  This
  was a thinko in previous commit. Now that stack base pointer is now
  set in PostmasterMain and SubPostmasterMain, it doesn't need to be
  set in PostgresMain anymore.
  http://git.postgresql.org/pg/commitdiff/03529a3ff999b0e4770b3e0b8e342400e383db98

== Rejected Patches (for now) ==

No one was disappointed this week :-)

== Pending Patches ==

Etsuro Fujita and Shigeru HANADA traded patches to implement various
parts of a PostgreSQL FDW.

Gilles Darold sent in some patches to help tell when PostgreSQL is in
backup mode.

Josh Kupershmidt sent in a patch to fix psql's tab completion for WITH
under some circumstances.

Heikki Linnakangas and Pavel Stehule traded versions of the CHECK
TRIGGER patch.

Joachim Wieland sent in two more revisions of the patch to make
pg_dump able to operate in parallel.

Yeb Havinga sent in two revisions of a patch intended to fix an issue
with cursor arguments in named notation.

Zoltan Boszormenyi sent in five revisions of a patch to implement a
framework to simplify and correctly nest multiplexing more than two
timeout sources into the same SIGALRM signal handler.

Robert Haas sent in a patch to fix the SLRU replacement algorithm.

Peter Eisentraut sent in a patch to rename bytea_agg() to
string_agg(), which now covers bytea types.

Peter Geoghegan sent in a patch to do some speedups in
pg_stat_statements.

Alvaro Herrera sent in another revision of the patch to add URI
support to libpq, along with some documentation fo the changes.