== Wöchentlicher PostgreSQL Newsletter - 17. April 2011 ==

Der Originalartikel befindet sich unter:

http://www.postgresql.org/community/weeklynews/pwn20110417



== Wöchentlicher PostgreSQL Newsletter - 17. April 2011 ==

PostgreSQL Updates 9.04, 8.4.8, 8.3.15, und 8.2.21 erscheinen bald.
Fertigmachen zum Upgrade!

== PostgreSQL Produkt Neuigkeiten ==

tail_n_mail 1.18.1, ein Programm zum Überwachen von
Logdateien, ist erschienen.
http://bucardo.org/wiki/Tail_n_mail

Bucardo 4.4.3, ein Postgres Multi-Master Replikationssystem,
ist erschienen.
http://bucardo.org/wiki/Bucardo

== PostgreSQL Jobs im April ==

http://archives.postgresql.org/pgsql-jobs/2011-04/threads.ph p

== PostgreSQL Lokal ==

Die Türkische PostgreSQL User Group organisiert eine eintägige
Veranstaltung am 30. April 2011. Folge @PgDayTR für Details,
auf Türkisch.
http://pgday.postgresql.org.tr/2011/

Das Open Database Camp findet vom 7. bis 9. Mai 2011 in Sardinien,
Italien statt.
http://datacharmer.blogspot.com/2011/01/announcing-open-data base-camp-sardi=
nia.html

PGCon findet am 19. und 20. Mai 2011 an der Universität
von Ottawa statt, vorher gibt es am 17. und 18. Mai
zwei Tage mit Trainings.
http://www.pgcon.org/2011/

PG Session 2 über PostGIS findet am 23. Juni in Paris statt.
Der Call for Papers ist jetzt offen.
http://www.postgresql-sessions.org/en/2/

pgbr findet in Sao Paulo, Brazilien, am 3. und 4. November 2011 statt.
http://pgbr.postgresql.org.br/

== PostgreSQL in den News ==

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

Dieser wöchentliche PostgreSQL Newsletter wurde erstellt von David Fet=
ter.

Sende Neuigkeiten und Ankündigungen bis Sonntag, 15 Uhr Pazifischer
Zeit. Bitte sende englische Beiträge an david@fetter.org, deutsche an
pwn@pgug.de, italienische an pwn@itpug.org, spanische an pwn@arpug.com.ar.

== Reviews ==

== Angewandte Patches ==

Heikki Linnakangas pushed:

- TransferPredicateLocksToNewTarget should initialize a new lock
entry's commitSeqNo to that of the old one being transferred, or
take the minimum commitSeqNo if it is merging two lock entries.
Also, CreatePredicateLock should initialize commitSeqNo for to
InvalidSerCommitSeqNo instead of to 0. (I don't think using 0 would
actually affect anything, but we should be consistent.) I also added
a couple of assertions I used to track this down: a lock's
commitSeqNo should never be zero, and it should be
InvalidSerCommitSeqNo if and only if the lock is not held by
OldCommittedSxact. Dan Ports, to fix leak of predicate locks
reported by YAMAMOTO Takashi.
=20
http://git.postgresql.org/pg/commitdiff/dad1f4638235e5ff5696 b948b88ba24cd99=
b415e

- Fix the size of predicate lock manager's shared memory hash tables
at creation. This way they don't compete with the regular lock
manager for the slack shared memory, making the behavior more
predictable.
=20
http://git.postgresql.org/pg/commitdiff/7c797e7194d969f974ab f579cacf30ffdcc=
dbb95

- On IA64 architecture, we check the depth of the register stack in
addition to the regular stack. The code to do that is platform and
compiler specific, add support for the HP-UX native compiler.
=20
http://git.postgresql.org/pg/commitdiff/b5bb040da63806f7386b 3434c38e1fa9886=
0ea88

- Revert the patch to check if we've reached end-of-backup also when
doing crash recovery, and throw an error if not. hubert depesz
lubaczewski pointed out that that situation also happens in the
crash recovery following a system crash that happens during an
online backup. We might want to do something smarter in 9.1, like
put the check back for backups taken with pg_basebackup, but that's
for another patch.
=20
http://git.postgresql.org/pg/commitdiff/54685b1c2b356b4b9c09 38f6b8dcc52e173=
c0400

- On HP/UX, the structs used by ioctl(SIOCGLIFCONF) are named
differently than on other platforms, and only IPv6 addresses are
returned. Because of those two issues, fall back to
ioctl(SIOCGIFCONF) on HP/UX, so that it at least compiles and finds
IPv4 addresses. This function is currently only used for
interpreting samehost/samenet in pg_hba.conf, which isn't that
critical.
=20
http://git.postgresql.org/pg/commitdiff/40e64017f3a4f1f7547d cbc62c2dcf80511=
ff842

- Reduce the initial size of local lock hash to 16 entries. The hash
table is seq scanned at transaction end, to release all locks, and
making the hash table larger than necessary makes that slower. With
very simple queries, that overhead can amount to a few percent of
the total CPU time used. At the moment, backend startup needs 6
locks, and a simple query with one table and index needs 3 locks. 16
is enough for even quite complicated transactions, and it will grow
automatically if it fills up.
=20
http://git.postgresql.org/pg/commitdiff/4c37c1e3b2a7ba7b5519 e5e366720e74448=
78a78

- setlocale() on Windows doesn't work correctly if the locale name
contains apostrophes or dots. There isn't much hope of Microsoft
fixing it any time soon, it's been like that for ages, so we better
work around it. So, map a few common Windows locale names known to
cause problems to aliases that work.
=20
http://git.postgresql.org/pg/commitdiff/d5a7bf8c11c8b66c822b bb1a6c90e1a1442=
5bd6e

- On Windows, if the encoding implied by locale is not allowed as a
server-encoding, fall back to UTF-8. It happens at least with the
Chinese locale, which implies BIG5. This is safe, because on Windows
all locales are compatible with UTF-8.
=20
http://git.postgresql.org/pg/commitdiff/1f943dc8fe1377d93253 fad9f01e4b0aa85=
99bbd

Tom Lane pushed:

- Teach pattern_fixed_prefix() about collations. This is necessary,
not optional, now that ILIKE and regexes are collation aware ---
else we might derive a wrong comparison constant for index optimized
pattern matches.
=20
http://git.postgresql.org/pg/commitdiff/3c381a55b0fa1c4ca328 211e39df8e1a715=
129cb

- Fix RI_Initial_Check to use a COLLATE clause when needed in its
query. If the referencing and referenced columns have different
collations, the parser will be unable to resolve which collation to
use unless it's helped out in this way. The effects are sometimes
masked, if we end up using a non-collation-sensitive plan; but if we
do use a mergejoin we'll see a failure, as recently noted by Robert
Haas. The SQL spec states that the referenced column's collation
should be used to resolve RI checks, so that's what we do. Note
however that we currently don't append a COLLATE clause when writing
a query that examines only the referencing column. If we ever
support collations that have varying notions of equality, that will
have to be changed. For the moment, though, it's preferable to
leave it off so that we can use a normal index on the referencing
column.
=20
http://git.postgresql.org/pg/commitdiff/921b993677e165607029 a52e7f866bbd112=
345a5

- Be more wary of missing statistics in eqjoinsel_semi(). In
particular, if we don't have real ndistinct estimates for both
sides, fall back to assuming that half of the left-hand rows have
join partners. This is what was done in 8.2 and 8.3 (cf
nulltestsel() in those versions). It's pretty stupid but it won't
lead us to think that an antijoin produces no rows out, as seen in
recent example from Uwe Schroeder.
=20
http://git.postgresql.org/pg/commitdiff/3f5d2fe3029b181fe773 a02f1d4b34624c3=
57634

- Suppress compiler warnings about "value computed is not used". The
recent patch to remove gcc 4.6 warnings created some new ones, at
least on my rather old gcc version. Try to make everybody happy by
casting to "void" when we just want to discard the result.
=20
http://git.postgresql.org/pg/commitdiff/88543ecfec9c754b5f14 b898bccbc68d941=
748b3

- Pass collations to functions in FunctionCallInfoData, not FmgrInfo.
Since collation is effectively an argument, not a property of the
function, FmgrInfo is really the wrong place for it; and this
becomes critical in cases where a cached FmgrInfo is used for
varying purposes that might need different collation settings. Fix
by passing it in FunctionCallInfoData instead. In particular this
allows a clean fix for bug #5970 (record_cmp not working). This
requires touching a bit more code than the original method, but
nobody ever thought that collations would not be an invasive
patch...
=20
http://git.postgresql.org/pg/commitdiff/d64713df7e5996ab3ab3 37b5e0901cf2c53=
773f9

- Fix broken pg_dump query. The 8.4 branch failed when talking to 7.0
servers. Per testing requested by Bruce.
=20
http://git.postgresql.org/pg/commitdiff/a2f9219e7053bf2395c5 0b198379d1073db=
c2298

- Add some useful cross-references to the CREATE EXTENSION reference
page. Per a suggestion from Josh Kupershmidt, though I modified his
patch quite a lot.
=20
http://git.postgresql.org/pg/commitdiff/dd95a1d3dd52cb9848d5 4ab9962156f666c=
4ca39

- Update time zone data files to tzdata release 2011f. DST law
changes in Chile, Cuba, Falkland Islands, Morocco, Samoa, Turkey.
Historical corrections for South Australia, Alaska, Hawaii.
=20
http://git.postgresql.org/pg/commitdiff/170aeb54074ae2e21b22 b79d1dd5c665700=
f7025

- Ensure mark_dummy_rel doesn't create dangling pointers in
RelOptInfos. When we are doing GEQO join planning, the current
memory context is a short-lived context that will be reset at the
end of geqo_eval(). However, the RelOptInfos for base relations are
set up before that and then re-used across many GEQO cycles. Hence,
any code that modifies a baserel during join planning has to be
careful not to put pointers to the short-lived context into the
baserel struct. mark_dummy_rel got this wrong, leading to
easy-to-reproduce-once-you-know-how crashes in 8.4, as reported
off-list by Leo Carson of SDSC. Some improvements made in 9.0 make
it difficult to demonstrate the crash in 9.0 or HEAD; but there's no
doubt that there's still a risk factor here, so patch all branches
that have the function. (Note: 8.3 has a similar function, but it's
only applied to joinrels and thus is not a hazard.)
=20
http://git.postgresql.org/pg/commitdiff/eca75a12a27d28b972fc 269c1c8813cd8eb=
15441

- Update release notes for releases 9.0.4, 8.4.8, 8.3.15, and 8.2.21.
=20
http://git.postgresql.org/pg/commitdiff/98eded936c1e81e6af5a 4228ba3eb7b6352=
d6c91

- Guard against incoming rowcount estimate of NaN in cost_mergejoin().
Although rowcount estimates really ought not be NaN, a bug elsewhere
could perhaps result in that, and that would cause Assert failure in
cost_mergejoin, which I believe to be the explanation for bug #5977
from Anton Kuznetsov. Seems like a good idea to expend a couple
more cycles to prevent that, even though the real bug is elsewhere.
Not back-patching, though, because we don't encourage running
production systems with Asserts on.
=20
http://git.postgresql.org/pg/commitdiff/72826fb362c4aada6d24 31df0b706df4488=
06c02

- Suppress unused-function warning on non-WIN32 builds.
=20
http://git.postgresql.org/pg/commitdiff/ff5565f0a4aa3c584792 d220a3e566369a7=
7f479

- Prevent incorrect updates of pg_index while reindexing pg_index
itself. The places that attempt to change pg_index.indcheckxmin
during a reindexing operation cannot be executed safely if pg_index
itself is the subject of the operation. This is the explanation for
a couple of recent reports of VACUUM FULL failing with
ERROR: duplicate key value violates unique constraint=20
"pg_index_indexrelid_index"
DETAIL: Key (indexrelid)=3D(2678) already exists.
However, there isn't any real need to update indcheckxmin in such a
situation, if we assume that pg_index can never contain a truly
broken HOT chain. This assumption holds if new indexes are never
created on it during concurrent operations, which is something we
don't consider safe for any system catalog, not just pg_index.
Accordingly, modify the code to not manipulate indcheckxmin when
reindexing any system catalog. Back-patch to 8.3, where HOT was
introduced. The known failure scenarios involve 9.0-style VACUUM
FULL, so there might not be any real risk before 9.0, but let's not
assume that.
=20
http://git.postgresql.org/pg/commitdiff/4b6106ccfea21e86943f 881edcf3cfc0366=
1a415

- Clean up collation processing in prepunion.c. This area was a few
bricks shy of a load, and badly under-commented too. We have to
ensure that the generated targetlist entries for a set-operation
node expose the correct collation for each entry, since higher-level
processing expects the tlist to reflect the true ordering of the
plan's output. This hackery wouldn't be necessary if
SortGroupClause carried collation info ... but making it do so would
inject more pain in the parser than would be saved here. Still, we
might want to rethink that sometime.
=20
http://git.postgresql.org/pg/commitdiff/121f49a00e432ee9cfad 7270d99504350cd=
1015f

- Simplify reindex_relation's API. For what seem entirely historical
reasons, a bitmask "flags" argument was recently added to
reindex_relation without subsuming its existing boolean argument
into that bitmask. This seems a bit bizarre, so fold them together.
=20
http://git.postgresql.org/pg/commitdiff/2d3320d3d256eed7ea3d eb8383348f2021e=
6a247

- Add an Assert that indexam.c isn't used on an index awaiting
reindexing. This might have caught the recent embarrassment over
trying to modify pg_index while its indexes were being rebuilt.
Noah Misch
=20
http://git.postgresql.org/pg/commitdiff/d2f60a3ab055fb61c8e1 056a7c5652f1dec=
85e00

- foreach() and list_delete() don't mix. Fix crash when releasing
duplicate entries in the encoding conversion cache list, caused by
releasing the current entry of the list being chased by foreach().
We have a standard idiom for handling such cases, but this loop
wasn't using it. This got broken in my recent rewrite of GUC assign
hooks. Not sure how I missed this when testing the modified code,
but I did. Per report from Peter.
=20
http://git.postgresql.org/pg/commitdiff/88dc6fa7a164c306d8a1 295769edb818d85=
20a3f

- Support a COLLATE clause in plpgsql variable declarations. This
allows the usual rules for assigning a collation to a local variable
to be overridden. Per discussion, it seems appropriate to support
this rather than forcing all local variables to have the
argument-derived collation.
=20
http://git.postgresql.org/pg/commitdiff/c94732585647437291ec 3f4a9902eeffc65=
a6945

- Add check for matching column collations in ALTER TABLE ... INHERIT.
The other DDL operations that create an inheritance relationship
were checking for collation match already, but this one got missed.
Also fix comments that failed to mention collation checks.
=20
http://git.postgresql.org/pg/commitdiff/49a642ab1802ea4cd80f 9c184e769921968=
8197f

- Fix pg_dump to handle collations applied to columns of composite
types. CREATE TYPE and ALTER TYPE ADD ATTRIBUTE handle this, so I
suppose it's an intended feature, but pg_dump didn't know about it.
=20
http://git.postgresql.org/pg/commitdiff/acfa1f45ed3ee2144581 954c77769056bd1=
49f5c

- Document COLLATE option in CREATE TYPE reference page. Curiously,
it was already documented in ALTER TYPE ADD ATTRIBUTE, but not here.
=20
http://git.postgresql.org/pg/commitdiff/2d4617126f6d708c5777 b378d9ef282fb2c=
08930

- Fix assorted infelicities in collation handling in psql's
describe.c. In \d, be more careful to print collation only if it's
not the default for the column's data type. Avoid assuming that the
name "default" is magic. Fix \d on a composite type so that it will
print per-column collations. It's no longer the case that a
composite type cannot have modifiers. (In consequence, the expected
outputs for composite-type regression tests change.) Fix \dD so that
it will print collation for a domain, again only if it's not the
same as the base type's collation.
=20
http://git.postgresql.org/pg/commitdiff/c29abc8b6f5334ac2f70 46a33b233776ead=
12395

Peter Eisentraut pushed:

- Clean up most -Wunused-but-set-variable warnings from gcc 4.6. This
warning is new in gcc 4.6 and part of -Wall. This patch cleans up
most of the noise, but there are some still warnings that are
trickier to remove.
=20
http://git.postgresql.org/pg/commitdiff/5caa3479c2efd31fca1b 271db687e5e57c7=
de2d4

- Translation updates.
=20
http://git.postgresql.org/pg/commitdiff/65a188e549a8bf7d0e18 0d7bbbf6823e77c=
953bb

- Rename pg_regress option --multibyte to --encoding. Also refactor
things a little bit so that the same methods for setting test locale
and encoding can be used everywhere.
=20
http://git.postgresql.org/pg/commitdiff/f536d4194293f900577c 728bfa4e62075a4=
c7da0

- Set client encoding explicitly in plpython_unicode test. This will
(hopefully) eliminate the need for the plpython_unicode_0.out
expected file.
=20
http://git.postgresql.org/pg/commitdiff/5809a6458450a59f8c4a 7a25beaefc81cff=
563d1

Andrew Dunstan pushed:

- Don't make "replication" magical as a user name, only as a database
name, in pg_hba.conf. Per gripe from Josh Berkus. Backported from
commit ed557a373c406bbb2a1843544ebbd856ca4cac47.
=20
http://git.postgresql.org/pg/commitdiff/290bb9b61c64afdb7b73 3837c0a00427b58=
745aa

Bruce Momjian pushed:

- Fix pg_upgrade crash. Fix pg_upgrade crash in 9.0 caused by a new
cluster database that doesn't exist in the old cluster; instead
throw an error. This was reported to me by EnterpriseDB testing
staff. This bug does not exist in git head.
=20
http://git.postgresql.org/pg/commitdiff/052e621cc2c25166037f e9fadd3082ae700=
45fec

Robert Haas pushed:

- Avoid incorrectly granting replication to roles created with
NOSUPERUSER. Andres Freund
=20
http://git.postgresql.org/pg/commitdiff/0a49c95c734d58385e9c 5e335088da1cd54=
e2344

- Fix toast table creation. Instead of using slightly-too-clever
heuristics to decide when we must create a TOAST table, just check
whether one is needed every time the table is altered. Checking
whether a toast table is needed is cheap enough that we needn't
worry about doing it on every ALTER TABLE command, and the previous
coding is apparently prone to accidental breakage: commit
04e17bae50a73af524731fa11210d5c3f7d8e1f9 broken ALTER TABLE .. SET
STORAGE, which moved some actions from AT_PASS_COL_ATTRS to
AT_PASS_MISC, and commit 6c5723998594dffa5d47c3cf8c96ccf89c033aae
broke ALTER TABLE .. ADD COLUMN by changing the way that adding
columns recurses into child tables. Noah Misch, with one comment
change by me
=20
http://git.postgresql.org/pg/commitdiff/39a68e5c6ca7b41b889e 773ca58535324af=
69630

- Remove obsolete comment. The lock level for adding a parent table
is now ShareUpdateExclusiveLock; see commit
fbcf4b92aa64d4577bcf25925b055316b978744a. This comment didn't get
updated to match, but it doesn't seem important to mention this
detail here, so rather than updating it now, just take it out.
=20
http://git.postgresql.org/pg/commitdiff/0c80b57d0775eb2015b7 672fd8b20c63846=
d2a0d

- Advise Debian/Ubuntu users to use openjade1.3. The latest openjade
packages for Ubuntu 10.10 seg fault when building our documentation.
Josh Berkus
=20
http://git.postgresql.org/pg/commitdiff/07e58cbe19d78027eec8 fd3e414220903b1=
25c97

Marc Fournier pushed:

- Tag 9.0.4, 8.4.8, 8.3.15, and 8.2.21.

Magnus Hagander pushed:

- Note that Bison on GnuWin32 has trouble with paths with spaces.
Peter Eisentraut
=20
http://git.postgresql.org/pg/commitdiff/3affae58b795fb238bed 17c35cadcefabdc=
1f0ee

- Specify which versions of the Platform SDK are supported. Anything
including Visual Studio 2010 compilers is not yet supported for
building on Windows.
=20
http://git.postgresql.org/pg/commitdiff/9e1526eddd34bf78327a 9e7be3db47a60b5=
9b688

== Abgelehnte Patches (bis jetzt) ==

No one was disappointed this week :-)

== Eingesandte Patches ==

Roman Zotov sent in another revision of the patch to turn PREFERRED
for type from a boolean to an int2, which allows for an expression of
precedence.

Robert Haas sent in a patch to fix a bug in recoveryStopsHere().

Greg Smith sent in a patch to remove some of the magic from running
pgindent.

Andrew Dunstan sent in two revisions of a patch to remove pgindent
magic in different ways from Greg Smith's.

--
Andreas 'ads' Scherbaum
Deutsche PostgreSQL User Group: http://www.pgug.de/
DPWN: http://andreas.scherbaum.la/blog/categories/18-PWN




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