---------- Forwarded message ----------
From: David Fetter <david at fetter.org>
Date: Mon, Aug 4, 2008 at 10:49 AM
Subject: [ANNOUNCE] == PostgreSQL Weekly News - August 03 2008 ==
To: PostgreSQL Announce <pgsql-announce at postgresql.org>


== PostgreSQL Weekly News - August 03 2008 ==

By the time you read this, the July Commitfest will be closed.  Lots
of new features went in.  In September's Commitfest, look for Common
Table Expressions and Windowing Functions.

== PostgreSQL Product News ==

Npgsql2 RC1 released.
http://www.npgsql.org

pgbouncer 1.2.1 released.
http://pgfoundry.org/projects/pgbouncer/

== PostgreSQL Local ==

pgDay San Francisco will be August 5.  Schedule:
http://pugs.postgresql.org/node/447
Register here:
http://www.linuxworldexpo.com/live/12/ehall//SN460564

The Prato Linux User Group will be having PostgreSQL talks in
September.  The schedule in Italian is:
http://www.prato.linux.it/serate_a_tema_2008

Sponsor the European PGDay!
http://www.pgday.org/en/sponsors/campaign

The Call for Papers for European PGDay has begun.
http://www.pgday.org/en/call4papers

PGCon Brazil 2008 will be on September 26-27 at Unicamp in Campinas.
http://pgcon.postgresql.org.br/index.en.html

PgDay.fr will be October 4 in Toulouse.  The Call for Papers is open:
http://www.postgresqlfr.org/?q=node/1686
Registration:
http://www.pgday.fr/doku.php/inscription

PGDay.(IT|EU) 2008 will be October 17 and 18 in Prato.
http://www.pgday.org/it/

== PostgreSQL in the News ==

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

General Bits, Archives and occasional new articles:
http://www.varlena.com/GeneralBits/

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.org, German language
to pwn at pgug.de, Italian language to pwn at itpug.org.

== Applied Patches ==

Tom Lane committed:

- Update 8.1 and 8.0 plpython to work with Python 2.5.  This backports
 several fixes made during the 8.2 development cycle, but not
 backported at the time for lack of confidence in the new coding.  I
 didn't touch 7.4 because it has more problems than this: the
 configure probe for Python fails.

- Add a new, improved version of citext as a contrib module.  David E.
 Wheeler.

- Replace the hard-wired type knowledge in TypeCategory() and
 IsPreferredType() with system catalog lookups, as was foreseen to be
 necessary almost since their creation.  Instead put the information
 into two new pg_type columns, typcategory and typispreferred.  Add
 support for setting these when creating a user-defined base type.
 The category column is just a "char" (i.e. a poor man's enum),
 allowing a crude form of user extensibility of the category list:
 just use an otherwise-unused character.  This seems sufficient for
 foreseen uses, but we could upgrade to having an actual category
 catalog someday, if there proves to be a huge demand for custom type
 categories.  In this patch I have attempted to hew exactly to the
 behavior of the previous hardwired logic, except for introducing new
 type categories for arrays, composites, and enums.  In particular
 the default preferred state for user-defined types remains TRUE.
 That seems worth revisiting, but it should be done as a separate
 patch from introducing the infrastructure.  Likewise, any adjustment
 of the standard set of categories should be done separately.

- Adjust citext to make use of the new ability to declare its type
 category: by putting it into the standard string category, we cause
 casts from citext to text to be recognized as "preferred" casts.
 This eliminates the need for creation of alias functions and
 operators that only serve to prevent ambiguous-function errors; get
 rid of the ones that were in the original commit.

- Flip the default typispreferred setting from true to false.  This
 affects only type categories in which the previous coding made
 *every* type preferred; so there is no change in effective behavior,
 because the function resolution rules only do something different
 when faced with a choice between preferred and non-preferred types
 in the same category.  It just seems safer and less surprising to
 have CREATE TYPE default to non-preferred status ...

- Allow I/O conversion casts to be applied to or from any type that is
 a member of the STRING type category, thereby opening up the
 mechanism for user-defined types.  This is mainly for the benefit of
 citext, though; there aren't likely to be a lot of types that are
 all general-purpose character strings.  Per discussion with David
 Wheeler.

- Require superuser privilege to create base types (but not
 composites, enums, or domains).  This was already effectively
 required because you had to own the I/O functions, and the I/O
 functions pretty much have to be written in C since we don't let PL
 functions take or return cstring.  But given the possible security
 consequences of a malicious type definition, it seems prudent to
 enforce superuser requirement directly.  Per recent discussion.

- Fix parser so that we don't modify the user-written ORDER BY list in
 order to represent DISTINCT or DISTINCT ON.  This gets rid of a
 longstanding annoyance that a view or rule using SELECT DISTINCT
 will be dumped out with an overspecified ORDER BY list, and is one
 small step along the way to decoupling DISTINCT and ORDER BY enough
 so that hash-based implementation of DISTINCT will be possible.  In
 passing, improve transformDistinctClause so that it doesn't reject
 duplicate DISTINCT ON items, as was reported by Steve Midgley a
 couple weeks ago.

- Rearrange the querytree representation of ORDER BY/GROUP BY/DISTINCT
 items as per my recent proposal: 1. Fold SortClause and GroupClause
 into a single node type SortGroupClause.  We were already relying on
 them to be struct-equivalent, so using two node tags wasn't
 accomplishing much except to get in the way of comparing items with
 equal().  2. Add an "eqop" field to SortGroupClause to carry the
 associated equality operator.  This is cheap for the parser to get
 at the same time it's looking up the sort operator, and storing it
 eliminates the need for repeated not-so-cheap lookups during
 planning.  In future this will also let us represent GROUP/DISTINCT
 operations on datatypes that have hash opclasses but no btree
 opclasses (ie, they have equality but no natural sort order).  The
 previous representation simply didn't work for that, since its only
 indicator of comparison semantics was a sort operator.  3. Add a
 hasDistinctOn boolean to struct Query to explicitly record whether
 the distinctClause came from DISTINCT or DISTINCT ON.  This allows
 removing some complicated and not 100% bulletproof code that
 attempted to figure that out from the distinctClause alone.  This
 patch doesn't in itself create any new capability, but it's
 necessary infrastructure for future attempts to use hash-based
 grouping for DISTINCT and UNION/INTERSECT/EXCEPT.

- In pgsql/src/test/regress/pg_regress.c, fix copy-and-pasteo that's
 causing pg_regress to lie about which file it can't read when the
 --temp-config argument is bad.  Noted while wondering why buildfarm
 member dungbeetle is failing ... this isn't why, but it is why the
 error report isn't very helpful ...

- In pgsql/src/backend/catalog/pg_type.c, tighten up the sanity checks
 in TypeCreate(): pass-by-value types must have a size that is one of
 the supported values, not just anything <= sizeof(Datum).
 Cross-check the alignment specification against size as well.

- Make GROUP BY work properly for datatypes that only support hashing
 and not sorting.  The infrastructure for this was all in place
 already; it's only necessary to fix the planner to not assume that
 sorting is always an available option.

Magnus Hagander committed:

- In pgsql/doc/src/sgml/install-win32.sgml, document which versions of
 ActivePerl and ActiveTcl are required for building on MSVC, and that
 the free distribution is enough (no need for the enterprise
 version).  Per gripe from Martin Zaun.

- In pgsql/doc/src/sgml/install-win32.sgml, clean up reference to
 config.pl so it makes sense not only in SGML source but in the
 actual web/pdf viewer...

- Move ident authentication code into auth.c along with the other
 authenciation routines, leaving hba.c to deal only with processing
 the HBA specific files.

- In pgsql/src/backend/libpq/auth.c, rearrange the code in auth.c so
 that all functions for a single authentication method is grouped
 together in a reasonably similar way, keeping the "global shared
 functions" together in their own section as well. Makes it a lot
 easier to find your way around the code.

Bruce Momjian committed:

- Add URL for TODO: "Consider decreasing the I/O caused by updating
 tuple hint bits."

Alvaro Herrera committed:

- Add a few more DTrace probes to the backend.  Robert Lor.

- Cope with Tcl versions that do not create a tclsh symlink to the
 version- numbered program.  Per persistent buildfarm failures.  Tom
 Lane.

== Rejected Patches (for now) ==

No one was disappointed this week :-)

== Pending Patches ==

Tatsuo Ishii sent in another revision of Yoshiuki Asaba's CTE patch.

Hitoshi Harada sent in another revision of his windowing functions
patch.

Jan Urbanski sent in two more revisions of his patch to add
selectivity functions for text search types.

KaiGai Kohei sent in another revision of his SE-PostgreSQL patch.

Abhijit Menon-Sen sent in two more revisions of his \ef (edit
function) patch for psql along with a patch to add
pg_get_functiondef() as an SQL-callable function.

Robert Lor sent in two more revisions of his DTrace probes patch.

ITAGAKI Takahiro sent in a patch to add STORAGE and reloptions to
CREATE TABLE ... LIKE.

Alvaro Herrera sent in two updates to Robert Lor's DTrace probes
patch.

ITAGAKI Takahiro sent in a patch to use NDirectFileRead and
NDirectFileWrite statistics counters for counting reads and writes in
BufFile.

Heikki Linnakangas sent in new revisions of his Relation Forks and FSM
rewrite patches, the latter depending on the former.


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-- 
$B2F at 6A3(B
Xia Qingran
qingran.xia at gmail.com
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