== PostgreSQL Weekly News - April 22 2007 ==

== PostgreSQL Weekly News - April 22 2007 ==

Bug fix releases 8.2.4, 8.1.9, 8.0.13, 7.4.17 and 7.3.19 will be out
soon.  Schedule that upgrade now :)

== PostgreSQL Product News ==

PgBouncer 1.0.7 released.
http://pgfoundry.org/projects/pgbouncer/

pgpool-II is Fedora Core and EPEL
Devrim GUNDUZ

PL/Proxy 2.0.2 released.
http://pgfoundry.org/projects/plproxy/

Skytools 2.1.4 released.
http://pgfoundry.org/projects/skytools/

== PostgreSQL Jobs for April ==

http://archives.postgresql.org/pgsql-jobs/2007-04/threads.php

== PostgreSQL Local ==

Get on the Road to PgDay!
http://www.pgday.it/en/node/95

Registration is open for PGCon 2007
http://www.pgcon.org/2007/registration.php

== PostgreSQL in the News ==

Planet PostgreSQL: http://www.planetpostgresql.org/

General Bits Archives:
http://www.varlena.com/GeneralBits/

PostgreSQL Weekly News is brought to you this week by David Fetter and
Devrim GUNDUZ.

To get your submission into the upcoming issue, make sure it arrives
at david@fetter.org or in German at pwn@pgug.de by Sunday at 3:00pm
Pacific Time.

== Applied Patches ==

Andrew Dunstan committed:

- Document new -with-libxslt build option.

Peter Eisentraut committed:

- In pgsql/contrib/uuid-ossp/uuid-ossp.sql.in, make some functions
  immutable.  Thanks, Marko Kreen

- Fix typo in contrib/uuid-ossp/README.uuid-ossp.

- Joachim Wieland's patch to make configuration parameters fall back
  to their default values when they are removed from the configuration
  file.

- Fix alignment of help output.

- A new contrib module uuid-ossp for generating UUID values using the
  OSSP UUID library.  New configure option --with-ossp-uuid to
  activate.

- Documentation for UUID type.

- Translation updates.

Bruce Momjian committed:

- Mark TODO as done: "Allow commenting of variables in postgresql.conf
  to restore them."

- Add comment on why deadlock detection error messages only prints
  numbers.

- Add script major_release_split to simplify creating release notes
  for multiple releases.

- Add mention of checking <link> behavior of HISTORY.html to release
  checklist.

- Remove duplicate text in FAQ, per Magnus Hagander.

- Release wording updates for releases 8.2.4, 8.1.9, 8.0.13, 7.4.17,
  7.3.19.

- Update FAQ to mention most recent release for releases 8.2.4, 8.1.9,
  8.0.13, 7.4.17, 7.3.19.

- Stamp releases 8.2.4, 8.1.9, 8.0.13, 7.4.17, 7.3.19.

- Update FAQ for 8.2.4.

- Release note updates for 8.2.4, 8.1.9, 8.0.13, 7.4.17, 7.3.19.

- Remove tabs from SGML source files.

- Item not done, per Pavel.

- Update docs/error message for CSV quote/escape --- must be ASCII.
  Backpatch doc change to 8.2.X.

- Update error message for COPY with a multi-byte delimiter.

- Document that the COPY delimiter must be an ASCII byte, rather than
  a multi-byte value.  It can also be a single-byte encoded character
  if the client and server versions match.  Backpatch to 8.2.X.

- Mark PL/PgSQL TODO sub-item as done: "Add support for WITH HOLD and
  SCROLL cursors."

- Mark PL/PgSQL TODO sub-item as done: "Add MOVE to cursors"

- Add warning about TODO item.

- Change TODO from easy to not, per Alvaro Herrera: "Set proper
  permissions on non-system schemas during db creation."

Magnus Hagander committed:

- Joachim Wieland's patch to fix the build for directories with spaces
  in them by quoting properly.

- Don't try to build uuid-ossp on msvc.

- Enable building of 64-bit libpq using visual studio 8 and the
  win32.mak file.  Enable building with kerberos support using the
  win32.mak file.  Patch by Hiroshi Saito and Magnus Hagander.

- Change default build to release, to be consistent with unix build.
  Make it possible to set the default from builenv.bat.  Per request
  from Dave Page.

- Silence mingw compiler warning.

- Merlin Moncure's patch which prevents psql from writing timing
  output in quiet mode.

- Enable IPV6 for all MSVC builds, including the VC6 libpq-only build.
  Per request from Hiroshi Saito.

Alvaro Herrera committed:

- Silence compiler warnings, per Bruce.

- Enable configurable log of autovacuum actions.  Initial patch from
  Simon Riggs, additional code and docs by me.  Per discussion.

- Add a multi-worker capability to autovacuum.  This allows multiple
  worker processes to be running simultaneously.  Also, now autovacuum
  processes do not count towards the max_connections limit; they are
  counted separately from regular processes, and are limited by the
  new GUC variable autovacuum_max_workers.  The launcher now has
  intelligence to launch workers on each database every
  autovacuum_naptime seconds, limited only on the max amount of worker
  slots available.  Also, the global worker I/O utilization is limited
  by the vacuum cost-based delay feature.  Workers are "balanced" so
  that the total I/O consumption does not exceed the established
  limit.  This part of the patch was contributed by ITAGAKI Takahiro.

Tom Lane committed:

- Remove some of the most blatant brain-fade in the recent guc patch
  (it's so nice to have a buildfarm member that actively rejects naked
  uses of strcasecmp).  This coding is still pretty awful, though,
  since it's going to be O(N^2) in the number of guc variables.  May I
  direct your attention to bsearch?

- Some further performance tweaks for planning large inheritance trees
  that are mostly excluded by constraints: do the CE test a bit
  earlier to save some adjust_appendrel_attrs() work on excluded
  children, and arrange to use array indexing rather than rt_fetch()
  to fetch RTEs in the main body of the planner.  The latter is
  something I'd wanted to do for awhile anyway, but seeing
  list_nth_cell() as 35% of the runtime gets one's attention.

- Avoid useless work during set_plain_rel_pathlist() when the relation
  will be excluded by constraint exclusion anyway.  Greg Stark.

- Tweak make_inh_translation_lists() to check the common case wherein
  parent and child attnums are the same, before it grovels through
  each and every child column looking for a name match.  Saves some
  time in large inheritance trees, per example from Greg Stark.

- Improve the way in which CatalogCacheComputeHashValue combines
  multiple key values: don't throw away perfectly good hash bits, and
  increase the shift distances so as to provide more separation in the
  common case where some of the key values are small integers (and so
  their hashes are too, because hashfunc.c doesn't try all that hard).
  This reduces the runtime of SearchCatCache by a factor of 4 in an
  example provided by Greg Stark, in which the planner spends a whole
  lot of time searching the two-key STATRELATT cache.  It seems
  unlikely to hurt in other cases, but maybe we could do even better?

- Adjust pgstat_initstats() to avoid repeated searches of the TabStat
  arrays when a relation is opened multiple times in the same
  transaction.  This is particularly useful for system catalogs, which
  we may heap_open or index_open many times in a transaction, and it
  doesn't really cost anything extra even if the rel is touched but
  once.  Motivated by study of an example from Greg Stark, in which
  pgstat_initstats() accounted for an unreasonably large fraction of
  the runtime.

- Tweak set_rel_width() to avoid redundant executions of getrelid().
  In very large queries this accounts for a noticeable fraction of
  planning time.  Per an example from Greg Stark.

- Sync timezone data with 2007e zic release.

- Fix missed PACKAGE_STRING.

- Fix plpgsql to avoid reference to already-freed memory when
  returning a pass-by-reference data type and the RETURN statement is
  within an EXCEPTION block.  Bug introduced by my fix of 2007-01-28
  to use per-subtransaction ExprContexts/EStates; since that wasn't
  back-patched into older branches, only 8.2 and HEAD are affected.
  Per report from Gary Winslow.

- Cancel pending fsync requests during WAL replay of DROP DATABASE,
  per bug report from David Darville.  Back-patch as far as 8.1, which
  may or may not have the problem but it seems a safe change anyway.

- Fix condition for whether end_heap_rewrite must fsync, per Heikki
  Linnakangas.

- Don't assume rd_smgr stays open across all of a rewriteheap
  operation; doing so can result in crash if an sinval reset occurs
  meanwhile.  I believe this explains intermittent buildfarm failures
  in cluster test.

- Rewrite choose_bitmap_and() to make it more robust in the presence
  of competing alternatives for indexes to use in a bitmap scan.  The
  former coding took estimated selectivity as an overriding factor,
  causing it to sometimes choose indexes that were much slower to scan
  than ones with a slightly worse selectivity.  It was also too
  narrow-minded about which combinations of indexes to consider
  ANDing.  The rewrite makes it pay more attention to index scan cost
  than selectivity; this seems sane since it's impossible to have very
  bad selectivity with low cost, whereas the reverse isn't true.
  Also, we now consider each index alone, as well as adding each index
  to an AND-group led by each prior index, for a total of about O(N^2)
  rather than O(N) combinations considered.  This makes the results
  much less dependent on the exact order in which the indexes are
  considered.  It's still a lot cheaper than an O(2^N) exhaustive
  search.  A prefilter step eliminates all but the cheapest of those
  indexes using the same set of WHERE conditions, to keep the
  effective value of N down in scenarios where the DBA has created
  lots of partially-redundant indexes.

- Fix erroneous column counts in some documentation tables.  Brian
  Gough.

- Temporarily re-add derived files, in hopes of straightening out
  their CVS status.  And remove 'em again ...

- Tweak clean_encoding_name() API to avoid need to cast away const.
  Kris Jurka

- Fix pg_dump to not crash if -t or a similar switch is used to select
  a serial sequence for dumping without also selecting its owning
  table.  Make it not try to emit ALTER SEQUENCE OWNED BY in this
  situation.  Per report from Michael Nolan.

- Make plancache store cursor options so it can pass them to planner
  during a replan.  I had originally thought this was not necessary,
  but the new SPI facilities create a path whereby queries planned
  with non-default options can get into the cache, so it is necessary.

- Support scrollable cursors (ie, 'direction' clause in FETCH) in
  plpgsql.  Pavel Stehule, reworked a bit by Tom.

- Expose more cursor-related functionality in SPI: specifically, allow
  access to the planner's cursor-related planning options, and provide
  new FETCH/MOVE routines that allow access to the full power of those
  commands.  Small refactoring of planner(), pg_plan_query(), and
  pg_plan_queries() APIs to make it convenient to pass the planning
  options down from SPI.  This is the core-code portion of Pavel
  Stehule's patch for scrollable cursor support in plpgsql; I'll
  review and apply the plpgsql changes separately.

== Rejected Patches (for now) ==

No one was disappointed this week :-)

== Pending Patches ==

ITAGAKI Takahiro sent in a patch which suppresses some warnings on
MingW.

Kris Jurka sent in a patch which removes a warning about const
qualifier from src/backend/utils/mb/encnames.c

Arul Shaji sent in another revision of his patch which implements
COPY-able csv log outputs.

ITAGAKI Takahiro sent in another revision of his load distributed
checkpoint patch.

Heikki Linnakangas sent in a patch reconciling his HOT patch with
MVCC-safe CLUSTER.

Pavel Stehule sent an updated patch to add MOVE to PL/PgSQL.

Guillaume Lelarge sent in a document patch which explains that
stats_row_level needs to be enabled if user wants to get last
vacuum/analyze execution time.