== Notiziario settimanale PostgreSQL - 3 maggio 2009 ==

(Traduzione parziale in lingua italiana delle PostgreSQL Weekly News a
cura di Gianni Ciolli <gianni(dot)ciolli(at)2ndquadrant(dot)it>)

OpenStreetMap si sposta su PostgreSQL:
http://blog.cleverelephant.ca/2009/04/openstreetmap-moves-to-postgresql.html

== Novità sul prodotto PostgreSQL ==

Rilasciata la versione 1.40 di autodoc, un sistema automatico di
documentazione per PostgreSQL.
http://pgfoundry.org/projects/autodoc/

== La novità della settimana di PostgreSQL 8.4 ==

Nuovi indici hash. Nell'ambito del Summer of Code di Google, è stato
fatto il tagliando ai nostri indici hash; adesso essi danno
prestazioni migliori degli indici B-Tree per le ricerche aventi per
oggetto una sola riga; pertanto vale la pena usarli.

Tuttavia, ricorda che i nuovi indici hash non passano indenni dalla
recovery, e quindi può essere necessario fare REINDEX nel caso di un
crash di sistema.

== Il suggerimento della settimana ==

Il modulo contrib "ltree" contiene una implementazione degli alberi
indicizzati, e può essere d'aiuto per rappresentare un filesystem o
una simile gerarchia nel vostro database.

== Offerte di lavoro su PostgreSQL per maggio 2009 ==

http://archives.postgresql.org/pgsql-jobs/2009-05/threads.php

== Notizie locali su PostgreSQL ==

Il PgDay di Florianopolis (Brasile) sarà il 22 maggio. Mettetevi in
contatto con Dickson S. Guedes (guedes AT guedesoft DOT net) per
partecipare o inviare un lavoro.
http://www.postgresql.org.br/eventos/pgday/sc

La Percona Performance Conference si svolgerà presso il Santa Clara
Convention Center, Santa Clara, California, USA
http://conferences.percona.com/

Nei giorni 21 e 22 maggio 2009 all'università di Ottawa, in Canada, si
terrà PGCon 2009. Nei due giorni precedenti si terranno dei
tutorials.
http://www.pgcon.org/2009/

Segnatevi la data: pgDay San Jose (USA). Domenica 19 luglio subito
prima di OSCON. Saranno presto annunciate ulteriori informazioni!
(incluso il call for papers)

Il 23 e 24 ottobre 2009 si svolgerà PGCon Brazil, presso Unicamp,
nella città di Campinas, stato di San Paolo.

== Rassegna stampa su PostgreSQL ==

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

Questo notiziario settimanale PostgreSQL è stato realizzato da David
Fetter e Josh Berkus; traduzione parziale in lingua italiana a cura di
Gianni Ciolli.

Notizie o annunci destinati a questo notiziario dovranno pervenire
entro la mezzanotte di domenica (le 15 nel fuso orario della
California). I comunicati in lingua italiana dovranno essere inviati a
pwn(at)itpug(dot)org; per le lingue inglese o tedesca, si scriva
rispettivamente a david(at)fetter(dot)org o a pwd(at)pgug(dot)de(dot)

== Patch applicate ==

Bruce Momjian committed:

- Proofreading adjustments for first two parts of documentation
(Tutorial and SQL).

- In pgsql/src/bin/scripts/vacuumdb.c, in VACUUM, FREEZE must be
before ANALYZE; fix this in vacuumdb. Docs are already correct.

- Blank line Makefile cleanups.

Heikki Linnakangas committed:

- In pgsql/src/backend/parser/gram.y, move SERVER to the right place
in the alphabetically sorted keyword list.

- Add pgsql/src/tools/check_keywords.pl script to perform some basic
sanity checks to the keyword lists in gram.y and kwlist.h. It
checks that all lists are in alphabetical order, and that all
keywords present in gram.y are listed in kwlist.h in the right
category, and that all keywords in kwlist.h are also in gram.y.
What's still missing is to check that all keywords defined with
"%token <keyword>" in gram.y are present in one of the keyword lists
in gram.y.

- In pgsql/src/tools/check_keywords.pl, clean up check_keywords.pl
script, making it 'strict' and removing a few leftover unused
variables. Laurent Laborde.

Tom Lane committed:

- Improve pull_up_subqueries logic so that it doesn't insert
unnecessary PlaceHolderVar nodes in join quals appearing in or below
the lowest outer join that could null the subquery being pulled up.
This improves the planner's ability to recognize constant join
quals, and probably helps with detection of common sort keys
(equivalence classes) as well.

- In pgsql/src/backend/utils/adt/datetime.c, when checking for
datetime field overflow, we should allow a fractional-second part
that rounds up to exactly 1.0 second. The previous coding rejected
input like "00:12:57.9999999999999999999999999999", with the exact
number of nines needed to cause failure varying depending on
float-timestamp option and possibly on platform. Obviously this
should round up to the next integral second, if we don't have enough
precision to distinguish the value from that. Per bug #4789 from
Robert Kruus. In passing, fix a missed check for fractional seconds
in one copy of the "is it greater than 24:00:00" code. Broken all
the way back, so patch all the way back.

- In pgsql/src/pl/plpgsql/src/gram.y, fix a couple of cases where the
plpgsql grammar looked for T_WORD and failed to consider the
possibility that it would get T_SCALAR, T_RECORD, or T_ROW instead
because the word happens to match a plpgsql variable name. In
particular, give "duplicate declaration" rather than generic "syntax
error" if the same identifier is declared twice in the same block,
as per my recent complaint. Also behave more sanely when
decl_aliasitem or proc_condition or opt_lblname is coincidentally
not T_WORD. Refactor the related productions a bit to reduce
duplication. This is a longstanding bug, but it doesn't seem
critical enough to back-patch.

- Fix plpgsql's EXIT so that an EXIT without a label only matches a
loop, never a BEGIN block. This is required for Oracle
compatibility and is also plainly stated to be the behavior by our
original documentation (up until 8.1, in which the docs were
adjusted to match the code's behavior; but actually the old docs
said the correct thing and the code was wrong). Not back-patched
because this introduces an incompatibility that could break working
applications. Requires release note.

- Split the release notes into a separate file for each (active) major
branch, as per my recent proposal. release.sgml itself is now just
a stub that should change rarely; ideally, only once per major
release to add a new include line. Most editing work will occur in
the release-N.N.sgml files. To update a back branch for a minor
release, just copy the appropriate release-N.N.sgml file(s) into the
back branch. This commit doesn't change the end-product
documentation at all, only the source layout. However, it makes it
easy to start omitting ancient information from newer branches'
documentation, should we ever decide to do that.

- We don't need major_release_split any more.

- Install some simple defenses in postmaster startup to help ensure a
useful error message if the installation directory layout is messed
up (or at least, something more useful than the behavior exhibited
in bug #4787). During postmaster startup, check that
get_pkglib_path resolves as a readable directory; and if
ParseTzFile() fails to open the expected timezone abbreviation file,
check the possibility that the directory is missing rather than just
the specified file. In case of either failure, issue a hint
suggesting that the installation is broken. These two checks cover
the lib/ and share/ trees of a full installation, which should take
care of most scenarios where a sysadmin decides to get cute.

- In pgsql/src/interfaces/libpq/fe-secure.c, fix already-obsolete hint
message ... sslverify parameter is no more.

- In pgsql/src/backend/utils/misc/guc.c, fix
assign_pgstat_temp_directory() to ensure the directory path is
canonicalized. Avoid the need to elog(FATAL) on out-of-memory.

- Fix unintelligible description created by removing only part of a
parenthetical remark.

- In pgsql/doc/src/sgml/func.sgml, fix mis-description of XML Schema
functions, per discussion.

- In pgsql/src/bin/pg_resetxlog/pg_resetxlog.c, fix pg_resetxlog to
remove archive status files along with WAL segment files. Fujii
Masao.

- In pgsql/src/backend/postmaster/postmaster.c, fix missed usage of
DLNewElem().

Tatsuo Ishii committed:

- pdate UTF-8 <--> EUC_KR, JOHAB, UHC mappings. Patch contributed by
Chuck McDevitt.

Alvaro Herrera committed:

- In pgsql/src/backend/postmaster/postmaster.c, avoid a memory
allocation in the backend startup code, to avoid having to check
whether it failed. Modelled after catcache.c's usage of DlList, per
suggestion from Tom Lane.

== Patch rifiutate (per adesso) ==

No one was disappointed this week :-)

== Patch in coda ==

Alvaro Herrera sent in a doc patch for autovacuum about when ANALYZE
is recommended.

Robert Haas sent in another revision of the ALTER COLUMN...SET
DISTINCT patch.

Robert Haas sent in a patch to replace a couple of references to files
that no longer exist in the source tree with references to the
appropriate URLs.