== Notiziario settimanale PostgreSQL - 14 giugno 2009 ==

== Notiziario settimanale PostgreSQL - 14 giugno 2009 ==

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

Presto uscirà PostgreSQL 8.4 RC1. Provatela!
http://www.postgresql.org/developer/beta

Nuovo sondaggio: qual è la tua massima priorità riguardo allo sviluppo
di PostgreSQL?
http://www.postgresql.org/community

Il progetto TikiWiki ha bisogno di aiuto Postgres! TikiWiki ha bisogno
di un nuovo maintainer della compatibilità PostgreSQL, in mancanza del
quale dovranno abbandonare il supporto PostgreSQL. Se usi TikiWiki e
puoi essere d'aiuto, allora sei pregato di metterti in contatto con
marclaporte AT tikiwiki DOT org.

== Novità sul prodotto PostgreSQL ==

Rilasciata la versione 1.7-SNAPSHOT di Mogwai ER-DesignerNG, uno
strumento ERD basato su Java.
http://mogwai.sourceforge.net/

Rilasciata la versione 1.1.4 di Slony1-ctl, un insieme di script per
la gestione di Slony.
http://pgfoundry.org/projects/slony1-ctl/

== La novità della settimana di PostgreSQL 8.4 ==

Il modulo aggiuntivo (contrib) pg_stat_statements permette di
tracciare le statistiche di esecuzione a livello di server. Capacity
planners, gioite!

== Il suggerimento della settimana ==

La parte referente ("figlio") delle chiavi esterne dovrebbe di solito
avere un indice, a meno che il valore abbia una cardinalità molto
bassa. Questo aspetto non è gestito automaticamente da PostgreSQL.

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

http://archives.postgresql.org/pgsql-jobs/2009-06/threads.php

== Notizie locali su PostgreSQL ==

Il pgDay di San Jose (USA) si terrà domenica 19 luglio 2009, dando il
via ad OSCON. Iscrivetevi qui:
http://postgresql.meetup.com/1/calendar/10626647

È aperto il CfP per PGCon Brazil, che si svolgerà Il 23 e 24 ottobre
2009 presso Unicamp, nella città di Campinas, stato di San Paolo.
http://pgcon.postgresql.org.br/2009/chamadas.en.php

Il PGDay.EU 2009 si terrà a Telecom ParisTech in Parigi nei giorni 6 e
7 novembre 2009.
http://www.pgday.eu/

Gli organizzatori della conferenza per il decimo anniversario di JPUG
stanno accettando proposte. La conferenza si terrà i giorni 20 e 21
novembre 2009 a Tokio.
http://archives.postgresql.org/pgsql-announce/2009-05/msg00018.php

== 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 ==

Tom Lane committed:

- In pgsql/doc/src/sgml/release-8.4.sgml, be a bit more verbose about
the effects of string literal processing changes in plpgsql. Per
bug #4843.

- Fix contrib/pageinspect to not create an ABI breakage between 8.3
and 8.4. The original implementation of the 3-argument form of
get_raw_page() risked core dumps if the 8.3 SQL function definition
was mistakenly used with the 8.4 module, which is entirely likely
after a dump-and-reload upgrade. To protect 8.4 beta testers
against upgrade problems, add a check on PG_NARGS. In passing, fix
missed additions to the uninstall script, and polish the docs a
trifle.

- In pgsql/src/backend/utils/adt/ruleutils.c, fix failure to
double-quote function argument names when needed, in
pg_get_function_arguments() and related functions. Per report from
Andreas Nolte.

- Restore dblink_current_query() to being a C-language function, so as
to not create an ABI break between 8.3 and 8.4. It is still just a
wrapper around the built-in current_query() function, but at a
different implementation level. Per my proposal. Note: this change
doesn't break 8.4beta installations, since their SQL-language
definition of the function still works fine.

- In pgsql/src/backend/utils/adt/array_userfuncs.c, switch order of
tests to avoid possible Assert failure for
"array_agg_finalfn(null)". We should modify pg_proc entries to
prevent this query from being accepted, but let's just make the
function itself secure too. Per my note of today.

- In pgsql/src/include/catalog/pg_proc.h, mark internal_in as not
strict, so that the construct "null::internal" will throw an error,
rather than possibly allowing someone to synthesize a manual call to
an internal-accepting function. As of CVS HEAD and existing
releases, all such functions are either STRICT or careful about null
inputs, so there is no current security issue here. But it seems
like a good idea to lock this down to protect against future
mistakes. In passing, similarly lock down trigger_in,
language_handler_in, opaque_in, and shell_in. These are not
believed to present any security risk, but there's still no good
reason to allow nulls of these types to be created. I left the
polymorphic pseudotypes (anyelement etc) alone, since a null of one
of those types doesn't seem to be a problem --- the worst you can
say about it is that it doesn't have an underlying non-polymorphic
type. If we were to make this change during normal development,
we'd just automatically bump catversion for a pg_proc.h change. But
since this doesn't create a compatibility risk and isn't believed to
be fixing a live bug, it seems better not to force a catversion bump
in late beta.

- In pgsql/src/backend/utils/adt/xml.c, ensure xmlFree(NULL) is a
no-op instead of a core dump. Per report from Sergey Burladyan,
there are at least some dank corners of libxml2 that assume this
behavior, even though their published documentation suggests they
shouldn't. This is only really a live problem in 8.3, but the code
is still there for possible debugging use in HEAD, so patch both
branches.

- Make handling of INTERVAL DAY TO MINUTE and INTERVAL DAY TO SECOND
input more consistent with other cases, by having an unlabeled
integer field be treated as a number of minutes or seconds
respectively. These cases are outside the spec (which insists on
full "dd hh:mm" or "dd hh:mm:ss" input respectively), so it's not
much help to us in deciding what to do. But with this change, it's
uniformly the case that an unlabeled integer will be considered as
being a number of the interval's rightmost field. The change also
takes us back to the 8.3 behavior of throwing error for certain
ambiguous inputs such as INTERVAL '1 2' DAY TO MINUTE. Per recent
discussion.

- In pgsql/src/backend/utils/adt/cash.c, fix cash_in() to behave
properly in locales where frac_digits is zero, eg Japan. Report and
fix by Itagaki Takahiro. Also fix CASHDEBUG printout format for
branches with 64-bit money type, and some minor comment cleanup.
Back-patch to 7.4, because it's broken all the way back.

- In pgsql/src/backend/access/heap/heapam.c, keep rs_startblock the
same during heap_rescan, so that a rescan of a SeqScan node starts
from the same place as the first scan did. This avoids surprising
behavior of scrollable and WITH HOLD cursors, as seen in Mark
Kirkwood's bug report of yesterday. It's not entirely clear whether
a rescan should be forced to drop out of the syncscan mode, but for
the moment I left the code behaving the same on that point. Any
change there would only be a performance and not a correctness
issue, anyway. Back-patch to 8.3, since the unstable behavior was
created by the syncscan patch.

- In pgsql/doc/src/sgml/ref/declare.sgml, add a warning about possible
strange behavior of volatile functions in cursors. This has always
been the case, but given the lack of user complaints about it, I'm
not going to bother back-patching this.

- In pgsql/doc/src/sgml/datatype.sgml, add warning that xpath()
doesn't work with non-UTF8 data.

- Support Kerberos on platforms where libcom_err depends on OpenSSL,
as reportedly is true on OpenBSD. Also support OpenBSD's spelling
of -Wl,--as-needed. Per Simon Bertrang.

- Properly mark pg_freespace() function as strict. Also update
uninstall script to match reality.

- Fix ill-advised whitespace prettification, per buildfarm.

- In pgsql/src/backend/foreign/foreign.c, somebody seems to have
thought they could get away without checking for
rsinfo->expectedDesc == NULL in deflist_to_tuplestore(), but that
doesn't look very safe to me. Noted in passing while studying
problem report from Greg Davidson.

- Fix things so that you can still do "select foo()" where foo is a
SQL function returning setof record. This used to work, more or
less accidentally, but I had broken it while extending the code to
allow materialize-mode functions to be called in select lists. Add
a regression test case so it doesn't get broken again. Per gripe
from Greg Davidson.

- Update time zone data files to tzdata release 2009i: DST law changes
in Bangladesh, Egypt, Jordan, Pakistan.

- Mark contrib's GiST and GIN opclass support functions as STRICT, for
safety. (Note: GiST penalty functions could possibly be non-strict,
but none are at present.)

- Remove our inadequate kluge that tried to get AIX's various broken
versions of getaddrinfo() to work. Instead, recommend updating the
OS to get a working version of getaddrinfo. Per recent discussions.

- Revisit AlterTableCreateToastTable's API once again, hoping to make
it what pg_migrator actually needs and not just a partial solution.
We have to be able to specify the OID that the new toast table
should be created with.

- In pgsql/doc/src/sgml/release-8.4.sgml, update release notes to
today.

- In pgsql/doc/src/sgml/installation.sgml, add info about minimum
recommended AIX fix levels, per Laurenz Albe.

- Fix several places where a function was declared static and then
defined without static. Per testing with a compiler that complains
about this.

- In pgsql/doc/src/sgml/gist.sgml, improve documentation about GiST
opclass support functions. Dimitri Fontaine.

- In pgsql/src/backend/parser/parse_oper.c, fix
get_sort_group_operators() so that it doesn't think arrays can be
grouped via hashing. Eventually we ought to make that possible, but
it won't happen for 8.4. Per yesterday's report from Robert Haas.

- Change test tables in copy2 regression test to be temporary tables.
This prevents autovacuum from reclaiming free space in them and
causing the test's output row order to change, which is causing
intermittent bogus failure reports in the buildfarm. Backpatch to
8.3. The issue exists further back, but since autovacuum was not on
by default before 8.3, it's not a problem for buildfarm testing.

Peter Eisentraut committed:

- In pgsql/src/backend/utils/adt/xml.c, fix map_sql_table_to_xmlschema()
with dropped attributes. Also backpatched to 8.3.

- Fix xmlattribute escaping XML special characters twice (bug #4822).
ITAGAKI Takahiro.

- Correct/improve the datetime_precision field in the information
schema. In particular, always show 0 for the date type instead of
null, and show 6 (the default) for time, timestamp, and interval
without a declared precision. This is now in fuller conformance
with the SQL standard. Also clarify the documentation about this.
Discovered and analyzed by Konstantin Izmailov and Tom Lane

- In pgsql/src/backend/access/gist/gist.c, improve capitalization and
punctuation in recently added GiST message.

- In pgsql/src/bin/psql/describe.c, clarify error message.

- In pgsql/src/pl/plpgsql/src/scan.l, clarify to the translator that
plpgsql_yyerror() deals with the translation of "syntax error", not
the literal string. This same change was made in the backend a
while ago; but it applies to plpgsql as well.

- In ecpg, arrange that the string "syntax error" generated by bison
is translated.

- Translation updates.

- In pgsql/src/bin/psql/describe.c, tweak the display of incoming
foreign-key constraints in \d, per discussion on hackers. Also,
take that string out of the translation roster, since it's now
entirely pseudo-SQL.

Joe Conway committed:

- In pgsql/contrib/dblink/dblink.c, default client encoding to server
encoding for dblink connections. Addresses issue raised by
Ruzsinszky Attila and confirmed by others.

Alvaro Herrera committed:

- In pgsql/src/backend/postmaster/autovacuum.c, dynamically set a
lower bound on autovacuum nap time so that we don't rebuild the
database list too often. Per bug report from Lukasz Jagiello and
ensuing discussion on pgsql-performance.

- In pgsql/src/backend/postmaster/autovacuum.c, fix typo, per Tom
Lane.

Bruce Momjian committed:

- In pgsql/src/tools/pgindent/README, document new location for
typedef list.

- In pgsql/src/tools/pgindent/README, update pgindent instructions.

- In pgsql/src/tools/find_typedef, fix BSD find_typedef logic.

- In pgsql/src/tools/find_typedef, fix Linux typedef code.

- In pgsql/src/tools/find_typedef, add FreeBSD support for
find_typedef, per request from Andrew Dunstan.

- 8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef list
provided by Andrew Dunstan.

- In pgsql/src/tools/pgindent/pgindent, document struct/union problem
with pgindent.

- In pgsql/src/tools/find_typedef, mention BSD/OS find_typedef
behavior.

- In pgsql/src/tools/find_typedef, tighten typedef check for Linux.

Marc Fournier committed:

- Time to tag rc1 ...

== Patch rifiutate (per adesso) ==

No one was disappointed this week :-)

== Patch in coda ==

Kedar Potdar sent in a patch targeted for 8.5 to allow automated
range- and hash-based partitioning.

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

Jeremy Kerr sent in three versions of a patch to refactor the
sigpipe-masking code in libpq from macros to private structs.

Kevin Grittner sent in a patch to make TOAST happen with less
enthusiasm.

Robert Haas sent in another revision of his patch refactoring EXPLAIN
for more generic output.

Robert Haas sent in another revision of his "generic options for
explain" patch.

Robert Haas sent in a patch to allow EXPLAIN to output in XML and
JSON. It depends on the two patches above.

Robert Haas sent in a patch to have do_tup_output() take Datums. This
is in aid of the EXPLAIN outputs above.

David Fetter and Petr Jelinek sent in patches to allow RETURNING in
CTEs.