E.166. Release 8.4.8
Release date: 2011-04-18
This release contains a variety of fixes from 8.4.7. For information about new features in the 8.4 major release, see Section E.174 .
E.166.1. Migration to Version 8.4.8
A dump/restore is not required for those running 8.4.X.
However, if your installation was upgraded from a previous major
release by running
pg_upgrade
, you should take
action to prevent possible data loss due to a now-fixed bug in
pg_upgrade
. The recommended solution is to run
VACUUM FREEZE
on all TOAST tables.
More information is available at
http://wiki.postgresql.org/wiki/20110408pg_upgrade_fix
.
Also, if you are upgrading from a version earlier than 8.4.2, see Section E.172 .
E.166.2. Changes
-
Fix pg_upgrade 's handling of TOAST tables (Bruce Momjian)
The
pg_class
.relfrozenxid
value for TOAST tables was not correctly copied into the new installation during pg_upgrade . This could later result inpg_clog
files being discarded while they were still needed to validate tuples in the TOAST tables, leading to " could not access status of transaction " failures.This error poses a significant risk of data loss for installations that have been upgraded with pg_upgrade . This patch corrects the problem for future uses of pg_upgrade , but does not in itself cure the issue in installations that have been processed with a buggy version of pg_upgrade .
-
Suppress incorrect " PD_ALL_VISIBLE flag was incorrectly set " warning (Heikki Linnakangas)
VACUUM
would sometimes issue this warning in cases that are actually valid. -
Disallow including a composite type in itself (Tom Lane)
This prevents scenarios wherein the server could recurse infinitely while processing the composite type. While there are some possible uses for such a structure, they don't seem compelling enough to justify the effort required to make sure it always works safely.
-
Avoid potential deadlock during catalog cache initialization (Nikhil Sontakke)
In some cases the cache loading code would acquire share lock on a system index before locking the index's catalog. This could deadlock against processes trying to acquire exclusive locks in the other, more standard order.
-
Fix dangling-pointer problem in
BEFORE ROW UPDATE
trigger handling when there was a concurrent update to the target tuple (Tom Lane)This bug has been observed to result in intermittent " cannot extract system attribute from virtual tuple " failures while trying to do
UPDATE RETURNING ctid
. There is a very small probability of more serious errors, such as generating incorrect index entries for the updated tuple. -
Disallow
DROP TABLE
when there are pending deferred trigger events for the table (Tom Lane)Formerly the
DROP
would go through, leading to " could not open relation with OID nnn " errors when the triggers were eventually fired. -
Prevent crash triggered by constant-false WHERE conditions during GEQO optimization (Tom Lane)
-
Improve planner's handling of semi-join and anti-join cases (Tom Lane)
-
Fix selectivity estimation for text search to account for NULLs (Jesper Krogh)
-
Improve PL/pgSQL's ability to handle row types with dropped columns (Pavel Stehule)
This is a back-patch of fixes previously made in 9.0.
-
Fix PL/Python memory leak involving array slices (Daniel Popowich)
-
Fix pg_restore to cope with long lines (over 1KB) in TOC files (Tom Lane)
-
Put in more safeguards against crashing due to division-by-zero with overly enthusiastic compiler optimization (Aurelien Jarno)
-
Support use of dlopen() in FreeBSD and OpenBSD on MIPS (Tom Lane)
There was a hard-wired assumption that this system function was not available on MIPS hardware on these systems. Use a compile-time test instead, since more recent versions have it.
-
Fix compilation failures on HP-UX (Heikki Linnakangas)
-
Fix version-incompatibility problem with libintl on Windows (Hiroshi Inoue)
-
Fix usage of xcopy in Windows build scripts to work correctly under Windows 7 (Andrew Dunstan)
This affects the build scripts only, not installation or usage.
-
Fix path separator used by pg_regress on Cygwin (Andrew Dunstan)
-
Update time zone data files to tzdata release 2011f for DST law changes in Chile, Cuba, Falkland Islands, Morocco, Samoa, and Turkey; also historical corrections for South Australia, Alaska, and Hawaii.