E.68.1. Migration to Version 8.4.1

A dump/restore is not required for those running 8.4.X.

E.68.2. Changes

• Fix WAL page header initialization at the end of archive recovery (Heikki)

  This could lead to failure to process the WAL in a subsequent archive recovery.

• Fix "cannot make new WAL entries during recovery" error (Tom)

• Fix problem that could make expired rows visible after a crash (Tom)

  This bug involved a page status bit potentially not being set correctly after a server crash.

• Disallow RESET ROLE and RESET SESSION AUTHORIZATION inside security-definer functions (Tom, Heikki)

  This covers a case that was missed in the previous patch that disallowed SET ROLE and SET SESSION AUTHORIZATION inside security-definer functions. (See CVE-2007-6600)

• Make LOAD of an already-loaded loadable module into a no-op (Tom)

  Formerly, LOAD would attempt to unload and re-load the module, but this is unsafe and not all that useful.

• Make window function PARTITION BY and ORDER BY items always be interpreted as simple expressions (Tom)

  In 8.4.0 these lists were parsed following the rules used for top-level GROUP BY and ORDER BY lists. But this was not correct per the SQL standard, and it led to possible circularity.

• Fix several errors in planning of semi-joins (Tom)

  These led to wrong query results in some cases where IN or EXISTS was used together with another join.

• Fix handling of whole-row references to subqueries that are within an outer join (Tom)

  An example is SELECT COUNT(ss.*) FROM ... LEFT JOIN (SELECT ...) ss ON .... Here, ss.* would be treated as ROW(NULL,NULL,...) for null-extended join rows, which is not the same as a simple NULL. Now it is treated as a simple NULL.

• Fix Windows shared-memory allocation code (Tsutomu Yamada, Magnus)

  This bug led to the often-reported "could not reattach to shared memory" error message.

• Fix locale handling with plperl (Heikki)

  This bug could cause the server's locale setting to change when a plperl function is called, leading to data corruption.

• Fix handling of reloptions to ensure setting one option doesn't force default values for others (Itagaki Takahiro)

• Ensure that a "fast shutdown" request will forcibly terminate open sessions, even if a "smart shutdown" was already in progress (Fujii Masao)

• Avoid memory leak for array_agg() in GROUP BY queries (Tom)

• Treat to_char(..., 'TH') as an uppercase ordinal suffix with 'HH'/'HH12' (Heikki)

  It was previously handled as 'th' (lowercase).

• Include the fractional part in the result of EXTRACT(second) and EXTRACT(milliseconds) for time and time with time zone inputs (Tom)

  This has always worked for floating-point datetime configurations, but was broken in the integer datetime code.

• Fix overflow for INTERVAL 'x ms' when x is more than 2 million and integer datetimes are in use (Alex Hunsaker)

• Improve performance when processing toasted values in index scans (Tom)

  This is particularly useful for PostGIS.

• Fix a typo that disabled commit_delay (Jeff Janes)

• Output early-startup messages to postmaster.log if the server is started in silent mode (Tom)

  Previously such error messages were discarded, leading to difficulty in debugging.

• Remove translated FAQs (Peter)

  They are now on the wiki. The main FAQ was moved to the wiki some time ago.

• Fix pg_ctl to not go into an infinite loop if postgresql.conf is empty (Jeff Davis)

• Fix several errors in pg_dump's --binary-upgrade mode (Bruce, Tom)

  pg_dump --binary-upgrade is used by pg_migrator.

• Fix contrib/xml2's xslt_process() to properly handle the maximum number of parameters (twenty) (Tom)

• Improve robustness of libpq's code to recover from errors during COPY FROM STDIN (Tom)

• Avoid including conflicting readline and editline header files when both libraries are installed (Zdenek Kotala)

• Work around gcc bug that causes "floating-point exception" instead of "division by zero" on some platforms (Tom)

• Update time zone data files to tzdata release 2009l for DST law changes in Bangladesh, Egypt, Mauritius.