PostgreSQL Weekly News – April 10 2011
== PostgreSQL Weekly News – April 10 2011 ==
Austin PUG will be meeting April 13:
NYCPUG will meet April 14 at 6pm. Details and RSVP below:
== PostgreSQL Product News ==
MicroOLAP Database Designer 1.8.0 Beta for PostgreSQL released.
pgbouncer 1.4.1, a lightweight connection pooler for PostgreSQL, released.
PostgreSQL Multiple Precision Arithmetic 1.0b1 released:
Pyrseas 0.1.0, a toolkit for PostgreSQL version control, released.
== PostgreSQL Jobs for April ==
== PostgreSQL Local ==
There will be a large PostgreSQL presence at the MySQL Conference and
Expo, April 11-14, 2011 in Santa Clara, California.
PostgreSQL Turkey User Group is organizing a one-day event at April
30, 2011. Follow @PgDayTR for details in Turkish.
Open Database Camp will be on May 7-9, 2011 in Sardinia, Italy
PGCon will be May 19-20, 2011 at the University of Ottawa, preceded by
two days of tutorials on May 17-18.
PG Session 2, on PostGIS, will be held on June 23rd in Paris. The CfP
pgbr will be in Sao Paulo, Brazil November 3-4, 2011.
== PostgreSQL in the News ==
Planet PostgreSQL: http://planet.postgresql.org/
PostgreSQL Weekly News is brought to you this week by David Fetter
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== Reviews ==
== Applied Patches ==
Alvaro Herrera pushed:
– Duplicate expansion of “direction” from FETCH’s synopsis into MOVE
– Uppercase <!ENTITY> and <!DOCTYPE> tags in SGML source. This
improves compatibility with external toolchains, such as those used
by some documentation translation tools. Gabriele Bartolini
– Update MSVC toolchain to match SGML entity uppercasing. Per Robert
– Change “Id” to “id” in some SGML tags. Gabriele Bartolini
Robert Haas pushed:
– Include pid in pg_lock_status() results even for SIREAD locks. Dan
– Add missing check on invocation of trusted procedures. KaiGai Kohei
– Merge synchronous_replication setting into synchronous_commit. This
means one less thing to configure when setting up synchronous
replication, and also avoids some ambiguity around what the behavior
should be when the settings of these variables conflict. Fujii
Masao, with additional hacking by me.
– Add casts from int4 and int8 to numeric. Joey Adams, per gripe from
Ramanujam. Review by myself and Tom Lane.
– Typo fixes. Erik Rijkers
– Repair some flakiness in CheckTargetForConflictsIn. When we release
and reacquire SerializableXactHashLock, we must recheck whether an
R/W conflict still needs to be flagged, because it could have
changed under us in the meantime. And when we release the partition
lock, we must re-walk the list of predicate locks from the
beginning, because our pointer could get invalidated under us. Bug
report #5952 by Yamamoto Takashi. Patch by Kevin Grittner.
– Fix some sloppiness in new PL/python get_source_line() function.
– Partially roll back overenthusiastic SSI optimization. When a
regular lock is held, Steve Singer can use that in lieu of a
predicate lock to detect rw conflicts; but if the regular lock is
being taken by a subtransaction, we can’t assume that it’ll commit,
so releasing the parent transaction’s lock in that case is a no-no.
– Fix bug in propagating ALTER TABLE actions to typed tables. We need
to propagate such actions to all typed table children of a given
type, not just the first one. Noah Misch
– Make psql use pg_table_size instead of pg_relation_size on 9.0+
servers. Per discussion, pg_table_size() is a more helpful number
than pg_relation_size(). Bernd Helmle, reviewed by Susanne Ebrecht
– Truncate the predicate lock SLRU to empty, instead of almost empty.
Otherwise, the SLRU machinery can get confused and think that the
SLRU has wrapped around. Along the way, regardless of whether we’re
truncating all of the SLRU or just some of it, flush pages after
truncating, rather than before. Kevin Grittner
Simon Riggs pushed:
– Update comments and credit doc proofreaders
– Centralise release note items related to recovery and replication
– Avoid assuming there will be only 3 states for synchronous_commit.
Also avoid hardcoding the current default state by giving it the
name “on” and replace with a meaningful name that reflects its
behaviour. Coding only, no change in behaviour.
Peter Eisentraut pushed:
– Update key words table for 9.1
– Add traceback information to PL/Python errors. This mimics the
traceback information the Python interpreter prints with exceptions.
– Replace the confusing exit_nicely() by an atexit/on_exit hook
– Update regression test files for PL/Python traceback patch.
– Allow pg_upgrade with PGCLIENTENCODING set. This used to work, but
since PGCLIENTENCODING is now a connection option variable,
pg_upgrade would prevent it.
– Add collation support on Windows (MSVC build). There is not yet
support in initdb to populate the pg_collation catalog, but if that
is done manually, the rest should work.
Tom Lane pushed:
– Revise the API for GUC variable assign hooks. The previous
functions of assign hooks are now split between check hooks and
assign hooks, where the former can fail but the latter shouldn’t.
Aside from being conceptually clearer, this approach exposes the
“canonicalized” form of the variable value to guc.c without having
to do an actual assignment. And that lets us fix the problem
recently noted by Bernd Helmle that the auto-tune patch for
wal_buffers resulted in bogus log messages about “parameter
“wal_buffers” cannot be changed without restarting the server”.
There may be some speed advantage too, because this design lets hook
functions avoid re-parsing variable values when restoring a previous
state after a rollback (they can store a pre-parsed representation
of the value instead). This patch also resolves a longstanding
annoyance about custom error messages from variable assign hooks:
they should modify, not appear separately from, guc.c’s own message
about “invalid parameter value”.
– Fix collations when we call transformWhereClause from outside the
parser. Previous patches took care of assorted places that call
transformExpr from outside the main parser, but I overlooked the
fact that some places use transformWhereClause as a shortcut for
transformExpr + coerce_to_boolean. In particular this broke
collation-sensitive index WHERE clauses, as per report from Thom
Brown. Trigger WHEN and rule WHERE clauses too. I’m not forcing
initdb for this fix, but any affected indexes, triggers, or rules
will need to be dropped and recreated.
– Fix SortTocFromFile() to cope with lines that are too long for its
buffer. The original coding supposed that a dump TOC file could
never contain lines longer than 1K. The folly of that was exposed
by a recent report from Per-Olov Esgard. We only really need to see
the first dozen or two bytes of each line, since we’re just trying
to read off the numeric ID at the start of the line; so there’s no
need for a particularly huge buffer. What there is a need for is
logic to not process continuation bufferloads. Back-patch to all
supported branches, since it’s always been like this.
– Fix plpgsql’s issues with dropped columns in rowtypes in 8.4 branch.
This is a back-patch of commit dcb2bda9b7042dbf43f876c94ebf35d951de10e9
of Aug 6 2009, which fixed assorted cases in which plpgsql would
fail to cope with composite types that contain any dropped columns.
Per discussion, this fix has been out in 9.0 for long enough to make
it improbable that it creates any new bugs, so this is a low-risk
fix. To make it even lower risk, I did not back-patch the changes
in execQual.c, but just accepted the duplication of code between
there and tupconvert.c. The added files tupconvert.h and
tupconvert.c match their current states in HEAD.
– Modernize dlopen interface code for FreeBSD and OpenBSD. Remove the
hard-wired assumption that __mips__ (and only __mips__) lacks dlopen
in FreeBSD and OpenBSD. This assumption is outdated at least for
OpenBSD, as per report from an anonymous 9.1 tester. We can
perfectly well use HAVE_DLOPEN instead to decide which code to use.
Some other cosmetic adjustments to make freebsd.c, netbsd.c, and
openbsd.c exactly alike.
– Tweaks for SSI out-of-shared memory behavior. If we call
hash_search() with HASH_ENTER, it will bail out rather than return
NULL, so it’s redundant to check for NULL again in the caller.
Thus, in cases where we believe it’s impossible for the hash table
to run out of slots anyway, we can simplify the code slightly. On
the flip side, in cases where it’s theoretically possible to run out
of space, we don’t want to rely on dynahash.c to throw an error;
instead, we pass HASH_ENTER_NULL and throw the error ourselves if a
NULL comes back, so that we can provide a more descriptive error
message. Kevin Grittner
– Add an example of WITH (UPDATE RETURNING) INSERT to the INSERT ref
page. Per a discussion with Gavin Flower. This barely scratches
the surface of potential WITH (something RETURNING) use cases, of
course, but it’s one of the simplest compelling examples I can think
– Avoid extra whitespace in the arguments of <indexterm>. As noted by
Thom Brown, this confuses the DocBook index processor; it fails to
merge entries that differ only in whitespace, and sorts them
unexpectedly as well. Seems like a toolchain bug, but I’m not going
to hold my breath waiting for a fix. Note: easiest way to find
these is to look for double spaces in HTML.index.
– Modify initdb to complain only when no usable system locales are
found. Per discussion, the original behavior seems too noisy. But
if things are so broken that none of the locales reported by
“locale -a” are usable, that’s probably worth warning about.
– Avoid an unnecessary syscache lookup in parse_coerce.c. All the
other fields of the constant are being extracted from the syscache
entry we already have, so handle collation similarly. (There don’t
seem to be any other uses for the new function at the moment.)
– Tweak collation setup for GIN index comparison functions. Honor
index column’s collation spec if there is one, don’t go to the
expense of calling get_typcollation when we can reasonably assume
that all GIN storage types will use default collation, and be sure
to set a collation for the comparePartialFn too.
– Fix make_greater_string to not have an undocumented collation
assumption. The previous coding worked only if ltproc->fn_collation
was always either DEFAULT_COLLATION_OID or a C-compatible locale.
While that’s true at the moment, it wasn’t documented (and in fact
wasn’t true when this code was committed…). But it only takes a
couple more lines to make its internal caching behavior
locale-aware, so let’s do that.
– Clean up minor collation issues in indxpath.c. Get rid of bogus
collation test in match_special_index_operator (even for ILIKE, the
pattern match operator’s collation doesn’t matter here, and even if
it did the test was testing the wrong thing). Fix broken looping
logic in expand_indexqual_rowcompare. Add collation check in
match_clause_to_ordering_op. Make naming and argument ordering more
consistent; improve comments.
– Don’t show unusable collations in psql’s \dO command. “Unusable”
collations are those not matching the current database’s encoding.
The former behavior inconsistently showed such collations some of
the time, depending on the details of the pattern argument.
– Adjust collation determination rules as per discussion. Remove
crude hack that tried to propagate collation through a
function-returning-record, ie, from the function’s arguments to
individual fields selected from its result record. That is just
plain inconsistent, because the function result is composite and
cannot have a collation; and there’s no hope of making this kind of
action-at-a-distance work consistently. Adjust regression test
cases that expected this to happen. Meanwhile, the behavior of
casting to a domain with a declared collation stays the same as it
was, since that seemed to be the consensus.
– Remove collate.linux.utf8.sql’s assumptions about “.utf8” in locale
names. Tweak the test so that it does not depend on the platform
using “.utf8” as the extension signifying that a locale uses UTF8
encoding. For the most part this just requires using the
abbreviated collation names “en_US” etc, though I had to work a bit
harder on the collation creation tests. This opens the door to
using the test on platforms that spell locales differently, for
example “.utf-8” or “.UTF-8”. Also, the test is now somewhat useful
with server encodings other than UTF8; though depending on which
encoding is selected, different subsets of it will fail for lack of
character set support.
– Fix ILIKE to honor collation when working in single-byte encodings.
The original collation patch only fixed the multi-byte code path.
This change also ensures that ILIKE’s idea of the case-folding rules
is exactly the same as str_tolower’s.
– Clean up overly complex code for issuing some related error
messages. The original version was unreadable, and not mechanically
– Teach regular expression operators to honor collations. This
involves getting the character classification and case-folding
functions in the regex library to use the collations infrastructure.
Most of this work had been done already in connection with the
upper/lower and LIKE logic, so it was a simple matter of
transposition. While at it, split out these functions into a
separate source file regc_pg_locale.c, so that they can be correctly
labeled with the Postgres project’s license rather than the
Scriptics license. These functions are 100% Postgres-written code
whereas what remains in regc_locale.c is still mostly not ours, so
lumping them both under the same copyright notice was getting more
and more misleading.
– Insert dummy “break”s to silence compiler complaints. Apparently
some compilers dislike a case label with nothing after it. Per
– Add some more mapping macros for Microsoft wide-character API. Per
Bruce Momjian pushed:
– Simplify structure of query used to gather database object
information in pg_upgrade.
– Preserve pg_largeobject_metadata.relfrozenxid in pg_upgrade. This
is needed only in 9.1 because only 9.0 had this and no one is
upgrading from a 9.0 beta to 9.0 anymore. We basically don’t
backpatch 9.0 beta fixes at this point.
– Have pg_upgrade properly preserve relfrozenxid in toast tables.
This fixes a pg_upgrade bug that could lead to query errors when
clog files are improperly removed.
– pgindent run before PG 9.1 beta 1.
Andrew Dunstan pushed:
– Avoid use of mixed slash style paths in arguments to xcopy in MSVC
builds. Some versions of xcopy, notably on Windows 7 don’t like it.
Backpatch to 8.3, where we first used xcopy.
– Latest consolidated typedef list from buildfarm.
– Backport changes to allow building with MinGW 64 bit compiler.
These changes have been in HEAD for some time with no ill effect.
They are only being backported to 9.0, as the required WINNT version
was not high enough before that.
– Don’t make “replication” magical as a user name, only as a database
name, in pg_hba.conf. Per gripe from Josh Berkus.
– Adjust regression tests on cube and ECPG for MinGW 64 bit compiler.
Backport to 9.0, we’re not supporting this compiler on earlier
– Remove CRLF line endings in new cube results file.
== Rejected Patches (for now) ==
No one was disappointed this week
== Pending Patches ==
Alexey Klyukin sent in an update of Selena Deckelmann’s patch to
create a validator for config files.
Tom Lane sent in a patch to document the revised API for GUC assign
hooks via changes to src/backend/utils/misc/README.
Shigeru HANADA sent in patches to implement comments on USER MAPPINGs,
part of SQL/MED.
Peter Eisentraut sent in a patch to fix an issue in the Windows build.
Heikki Linnakangas sent in a patch to have the parser emit an InExpr
node type (similar to the extant CaseExpr), which allows the optimizer
to rearrange IN() to OR() in cases where it is safe to do so.
Shigeru HANADA sent in a patch to implement comments on FOREIGN DATA
WRAPPER and SERVER objects, which are part of SQL/MED.
Josh Kupershmidt sent in a doc patch suggesting using openjade 1.3
rather than 1.4devel as part of the doc build toolset.
KaiGai Kohei sent in a patch for the SE-PostgreSQL supplied module
which checks the process:transition permission between the labels
involved when a client’s label changes.
Noah Misch sent in another patch to fix an incompatibility between
pg_dump –binary-upgrade and ALTER TYPE … DROP ATTRIBUTE.
Noah Misch sent in a patch to fix an issue where
pg_attribute.attinhcount was incorrect.
Peter Eisentraut sent in a patch to add automatic pg_upgrade tests.
Peter Eisentraut sent in a patch to help fix some issues with
collation support on Windows.
Muhammad Usama sent in a patch to remove an extra linefeed from
Agent M sent in a patch to use POSIX shared memory, this one
accounting for multiple-postmaster start race conditions.
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