E.51.1. Migration to Version 8.4.18

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

However, if you are upgrading from a version earlier than 8.4.17, see Section E.52.

E.51.2. Changes

• Prevent corruption of multi-byte characters when attempting to case-fold identifiers (Andrew Dunstan)

  PostgreSQL case-folds non-ASCII characters only when using a single-byte server encoding.

• Fix memory leak caused by lo_open() failure (Heikki Linnakangas)

• Fix memory overcommit bug when work_mem is using more than 24GB of memory (Stephen Frost)

• Fix deadlock bug in libpq when using SSL (Stephen Frost)

• Properly compute row estimates for boolean columns containing many NULL values (Andrew Gierth)

  Previously tests like col IS NOT TRUE and col IS NOT FALSE did not properly factor in NULL values when estimating plan costs.

• Prevent pushing down WHERE clauses into unsafe UNION/INTERSECT subqueries (Tom Lane)

  Subqueries of a UNION or INTERSECT that contain set-returning functions or volatile functions in their SELECT lists could be improperly optimized, leading to run-time errors or incorrect query results.

• Fix rare case of "failed to locate grouping columns" planner failure (Tom Lane)

• Improve view dumping code's handling of dropped columns in referenced tables (Tom Lane)

• Fix possible deadlock during concurrent CREATE INDEX CONCURRENTLY operations (Tom Lane)

• Fix regexp_matches() handling of zero-length matches (Jeevan Chalke)

  Previously, zero-length matches like '^' could return too many matches.

• Fix crash for overly-complex regular expressions (Heikki Linnakangas)

• Fix regular expression match failures for back references combined with non-greedy quantifiers (Jeevan Chalke)

• Prevent CREATE FUNCTION from checking SET variables unless function body checking is enabled (Tom Lane)

• Fix pgp_pub_decrypt() so it works for secret keys with passwords (Marko Kreen)

• Remove rare inaccurate warning during vacuum of index-less tables (Heikki Linnakangas)

• Avoid possible failure when performing transaction control commands (e.g ROLLBACK) in prepared queries (Tom Lane)

• Ensure that floating-point data input accepts standard spellings of "infinity" on all platforms (Tom Lane)

  The C99 standard says that allowable spellings are inf, +inf, -inf, infinity, +infinity, and -infinity. Make sure we recognize these even if the platform's strtod function doesn't.

• Expand ability to compare rows to records and arrays (Rafal Rzepecki, Tom Lane)

• Update time zone data files to tzdata release 2013d for DST law changes in Israel, Morocco, Palestine, and Paraguay. Also, historical zone data corrections for Macquarie Island.