== Wöchentlicher PostgreSQL Newsletter - 11. November 2007 ==

Der Originalartikel befindet sich unter:
http://people.planetpostgresql.org/dfetter/index.php?/archives/144-Postgres-Weekly-News-November-11-2007.html

== Wöchentlicher PostgreSQL Newsletter - 11. November 2007 ==

8.3 Beta 3 kommt später diese Woche.

gborg.postgresql.org ist tot. Lang lebe pgfoundry.org!

== PostgreSQL Produkt Neuigkeiten ==

Cybercluster 1.0.0 erschienen.
http://pgfoundry.org/projects/cybercluster/

Npgsql2 Beta1 erschienen.
http://pgfoundry.org/projects/npgsql/

pgloader 2.2.2 erschienen.
http://pgfoundry.org/projects/pgloader/

== PostgreSQL Jobs im November ==

http://archives.postgresql.org/pgsql-jobs/2007-11/threads.php

== PostgreSQL Lokal ==

SFPUG trifft sich am 13. November um 19:30 im Hyperic. Anmeldunten unter:
http://postgresql.meetup.com/1/calendar/6522343/

== PostgreSQL in den News ==

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

General Bits, Archive und gelegentliche News Artikel:
http://www.varlena.com/GeneralBits/

Dieser wöchentliche PostgreSQL Newsletter wurde erstellt von David Fetter

Sende Neuigkeiten und Ankündigungen bis Sonntag, 15 Uhr Pazifischer
Please send English language ones to david(at)fetter(dot)org, German language
to pwn(at)pgug(dot)de, Italian language to pwn(at)itpug(dot)org(dot)

== Angewandte Patches ==

Joe Conway committed:

- Have crosstab variants treat NULL rowid as a category in its own
right, per suggestion from Tom Lane. This fixes crash-bug reported
by Stefan Schwarzer. Back-patched to 7.3.

Alvaro Herrera committed:

- In pgsql/doc/src/sgml/acronyms.sgml, point to our own UUID page
instead of to Wikipedia.

Peter Eisentraut committed:

- Use "alternative" instead of "alternate" where it is clearer.

- Error message cleanup in pg_dump and pg_dumpall.

- In pgsql/doc/src/sgml/sources.sgml, specify putting two spaces after
sentence-ending period, which is current practice also.

- Improve wording in pgsql/src/bin/pg_resetxlog/pg_resetxlog.c.

- Make captalization consistent in pgsql/src/bin/psql/describe.c.

- In pgsql/doc/src/sgml/ref/cluster.sgml, <optional> cannot be used
here, because psql doesn't handle it.

- In pgsql/src/bin/pg_dump/pg_dump.c, add missing newlines to error
messages and normalize wording a bit.

- In pgsql/src/backend/utils/adt/xml.c, improve error message.

- Small fixes to pgsql/doc/src/sgml/func.sgml.

- In pgsql/doc/src/sgml/datatype.sgml, mention text search instead of
tsearch2.

- In pgsql/src/backend/port/win32_shmem.c, add sentence-ending
periods.

- Wording changes in pgsql/src/backend/postmaster/postmaster.c.

- In pgsql/src/test/regress/expected/xml_1.out, adjust test results
for message changes. Darn.

- After conferencing again with Bruce, put in more accurate XML error
message.

- Allow XML processing instructions starting with "xml" while
prohibiting those being exactly "xml". Bug #3735 from Ben Leslie

Michael Meskes committed:

- Fixed two parser bugs in ecpg.

- Add missing clause to parser.

Magnus Hagander committed:

- Fix typos in pgsql/doc/src/sgml/textsearch.sgml. Guillaume Lelarge.

- Add parameter krb_realm used by GSSAPI, SSPI and Kerberos to
validate the realm of the connecting user. By default it's empty
meaning no verification, which is the way Kerberos authentication
has traditionally worked in PostgreSQL.

Bruce Momjian committed:

- Document txid functions. Marko Kreen.

- Move txid snapshot field description table from datatype to
functions section.

- Remove <sect1> of txid functions.

- In pgsql/src/tools/fsync/test_fsync.c, properly pass third argument
to open() in fsync test program. Hiroshi Saito

- In pgsql/doc/src/sgml/config.sgml, document that syncronhous commit
can be turned off in a single multi-statement transaction.

- Document that configure option --with-ossp-uuid only affects
contrib/uuid-ossp.

- Move NFS section into "Creating Cluster" documentation section
because it seems more logical there.

- In pgsql/doc/src/sgml/high-availability.sgml, add "High
Availability, Load Balancing, and Replication Feature Matrix" table
to docs.

- In pgsql/doc/src/sgml/high-availability.sgml, properly indent SGML
file.

- In pgsql/doc/src/sgml/high-availability.sgml, add mention of
pl/proxy toolset to docs.

- Wording improvement for pl/proxy mention.

- In tsearch code, remove !(A && B) via restructuring, for clarity.

- Move pl/proxy into Multi-server parallel query execution
documentation section.

- Properly order pg_ctl -c option alphabetically in docs.

- Reduce error level of ROLLBACK outside a transaction from WARNING to
NOTICE.

- Have text search thesaurus files use "?" for stop words. Throw an
error for actual stop words, rather than a warning. This fixes
problems with cache reloading causing warning messages. Re-enable
stop words in regression tests; was disabled by Tom. Document "?"
as API change.

- In pgsql/config/install-sh, use strip -x on OS/X-darwin because
non-"-x" causes link problems:
http://archives.postgresql.org/pgsql-hackers/2007-10/msg01470.php

- Update high availability documentation with comments from Markus
Schiltknecht.

- High availability wording fix.

- Add pg_ctl -t/timeout parameter to control amount of time to wait
for start/shutdown.

- Move most /contrib README files into SGML. Some still need
conversion or will never be converted. Albert Cervera i Areny.

- Remove references to READMEs from /contrib Makefiles.

- Make /contrib install/uninstall script consistent: remove
transactions, use create or replace function, make formatting
consistent, and set search_path on first line. Add documentation on
modifying *.sql to set the search_patch, and mention that major
upgrades should still run the installation scripts. Some of these
issues were spotted by Tom today.

- Adjust pg_trgm expected output for new *.sql file.

- Remove /contrib/dblink/doc directory, now in SGML.

- Remove tabs from SGML files.

- In pgsql/doc/src/sgml/intarray.sgml, trim trailing whitespace ---
needed commit to update anoncvs.

Tom Lane committed:

- In pgsql/src/include/access/tuptoaster.h, add a note about another
issue that needs to be considered before changing the TOAST size
thresholds.

- In pgsql/doc/src/sgml/func.sgml, minor editorial improvements to
txid functions' documentation: put back some text that got dropped,
improve markup, improve descriptions of snapshot components.

- Improve conversion of legacy CREATE CONSTRAINT TRIGGER
representation of foreign keys, one more time. Insist on matching
up all three triggers before we create a constraint; this will avoid
creation of duplicate constraints in scenarios where a broken FK
constraint was repaired by re-adding the constraint without removing
the old partial trigger set. Basically, this will work nicely in
all cases where the FK was actually functioning correctly in the
database that was dumped. It will fail to restore an FK in just one
case where we theoretically could restore it: where we find the
referenced table's triggers and not the referencing table's trigger.
However, in such a scenario it's likely that the user doesn't even
realize he still has an FK at all (since the more-likely-to-fail
cases aren't enforced), and we'd probably not accomplish much except
to cause the reload to fail because the data doesn't meet the FK
constraint. Also make the NOTICE logging still more verbose, by
adding detail about which of the triggers were found. This seems
about all we can do without solving the problem of getting the
user's attention at session end.

- In pgsql/src/interfaces/ecpg/ecpglib/prepare.c, fix
deprecated-by-C-spec usage: storage class should come before const
decoration. Zdenek Kotala

- Fix xmlelement() to initialize libxml correctly before using it, and
to avoid assuming that evaluation of its input expressions won't
change the state of libxml. This requires refactoring xml_init() to
not call xmlInitParser(), since now not all of its callers want
that. I also tweaked things to avoid repeated execution of
one-time-only tests inside xml_init(), though this is mostly for
clarity rather than in hopes of saving any noticeable amount of
runtime. Per report from Sheikh Amjad and subsequent discussion.
In passing, fix a couple of inadequately schema-qualified queries.

- Some code review for xml.c: Add some more xml_init() calls that
might not be necessary, but seem like a good idea to avoid possible
problems like we saw in xmlelement(). Fix unsafe assumption that
you can keep using the tupledesc of a relcache entry you don't have
open. Add missing error checks for SearchSysCache failure. Get rid
of handwritten array traversal in xpath() and O(N^2),
broken-for-nulls array access code in map_sql_value_to_xml_value(),
in favor of using deconstruct_array. Manually adjust a lot of line
breaks in places where the code is otherwise gonna look pretty awful
after pg_indent hacks it up (original author seems to have liked to
lay out code for a 200-column window).

- Fix patternsel() and callers to do the right thing for NOT LIKE and
the other negated-match operators. patternsel had been using the
supplied operator as though it were a positive-match operator, and
thus obtaining a wrong result, which was even more wrong after the
caller subtracted it from 1. Seems cleanest to give patternsel an
explicit "negate" argument so that it knows what's going on. Also
install the same factorization scheme for pattern join selectivity
estimators; even though they are just stubs at the moment, this may
keep someone from making the same type of mistake when they get
filled out. Per report from Greg Mullane. Backpatch to 8.2 ---
previous releases do not show the problem because patternsel()
doesn't actually use the operator directly.

- Improve the performance of LIKE/regex estimation in non-C locales,
by making make_greater_string() try harder to generate a string
that's actually greater than its input string. Before we just
assumed that making a string that was memcmp-greater was enough, but
it is easy to generate examples where this is not so when the locale
is not C. Instead, loop until the relevant comparison function
agrees that the generated string is greater than the input.
Unfortunately this is probably not enough to guarantee that the
generated string is greater than all extensions of the input, so we
cannot relax the restriction to C locale for the LIKE/regex index
optimization. But it should at least improve the odds of getting a
useful selectivity estimate in prefix_selectivity(). Per example
from Guillaume Smet. Backpatch to 8.1, mainly because that's what
the complainant is using...

- Last week's patch for make_sort_from_pathkeys wasn't good enough: it
has to be able to discard top-level RelabelType nodes on *both*
sides of the equivalence-class-to-target-list comparison, since
make_pathkey_from_sortinfo might either add or remove a RelabelType.
Also fix the latter to do the removal case cleanly. Per example
from Peter.

- Fix EquivalenceClass code to handle volatile sort expressions in a
more predictable manner; in particular that if you say ORDER BY
output-column-ref, it will in fact sort by that specific column even
if there are multiple syntactic matches. An example is
SELECT random() AS a, random() AS b FROM ... ORDER BY b, a;
While the use-case for this might be a bit debatable, it worked as
expected in earlier releases, so we should preserve the behavior for
8.3. Per my recent proposal. While at it, fix convert_subquery_pathkeys()
to handle RelabelType stripping in both directions; it needs this
for the same reasons make_sort_from_pathkeys does.

- If an index depends on no columns of its table, give it a dependency
on the whole table instead, to ensure that it goes away when the
table is dropped. Per bug #3723 from Sam Mason. Backpatch as far
as 7.4; AFAICT 7.3 does not have the issue, because it doesn't have
general-purpose expression indexes and so there must be at least one
column referenced by an index.

- Second pass at improving LIKE/regex estimation in non-C locales. It
turns out that it's actually quite likely that a string that is an
extension of the given prefix will sort as larger than the "greater"
string our previous code created. To provide some defense against
that, do the comparisons against a modified string instead of just
the bare prefix. We tack on "Z", "z", "y", or "9", whichever is
seen as largest in the current locale. Testing suggests that this
is sufficient at least for cases involving ASCII data.

- Clean up ts_locale.h/.c. Fix broken and
not-consistent-across-platforms behavior of wchar2char/char2wchar;
this should resolve bug #3730. Avoid excess computations of
pg_mblen in t_isalpha and friends. Const-ify APIs where possible.

- Add an expected-results file to get regression to pass cleanly in
sv_SE locale, which sorts a bit differently. Per recent gripe from
Magnus.

- Recognize RETURN QUERY via a textual test, so that QUERY doesn't
need to be a plpgsql keyword. This avoids springing a new reserved
word on plpgsql programmers. For consistency, handle RETURN NEXT
the same way.

- Fix markup problem with recent pg_ctl change.

- xmlGetUTF8Char()'s second argument is both input and output. Fix
uninitialized value, and avoid invoking the function nine separate
times in the pg_xmlIsNameChar macro. Should resolve buildfarm
failures. Per report from Ben Leslie.

- Add missing closing / in xsd:restriction, and remove some
unnecessary spaces for consistency. Per bug #3734 from Ben Leslie;
fix by Euler Taveira de Oliveira.

- Add an example of a SQL function with output parameters returning
multiple rows. I had thought this case was covered, but there was
no example in the obvious section to look in.

- Ensure that typmod decoration on a datatype name is validated in all
cases, even in code paths where we don't pay any subsequent
attention to the typmod value. This seems needed in view of the
fact that 8.3's generalized typmod support will accept a lot of
bogus syntax, such as "timestamp(foo)" or "record(int, 42)" --- if
we allow such things to pass without comment, users will get
confused. Per a recent example from Greg Stark. To implement this
in a way that's not very vulnerable to future bugs-of-omission,
refactor the API of parse_type.c's TypeName lookup routines so that
typmod validation is folded into the base lookup operation. Callers
can still choose not to receive the encoded typmod, but we'll check
the decoration anyway if it's present.

D'Arcy J.M. Cain committed:

- In pgsql/doc/src/sgml/datatype.sgml, remove deprecation notice and
add comment about safely restoring backups. As per discussion on
hackers.

Neil Conway committed:

- Use LOG instead of DEBUG2 for logging invalid cancel requests. (That
is, cancel requests with an incorrect key, or with a non-existent
PID). Per recent discussion on -hackers.

== Abgelehnte Patches (bis jetzt) ==

No one was disappointed this week :-)

== Eingesandte Patches ==

Zdenek Kotala sent in a patch to make pg_dump independent of
postgres.h.

Pavel Stehule sent in a tsearch2-compatible wrapper for the integrated
full-text search.

Jan Urbanski sent in a patch to tsearch2 which adds a dictionary that
only filters out stop words.

Bruce Momjian sent in a patch which uses "?" to mark stop words in the
thesaurus file.

Bruce Momjian sent in a patch which downgrades ROLLBACK while not in a
transaction from WARNING to NOTICE.

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