Log Message:
Changes 8.4.9:
* Fix bugs in indexing of in-doubt HOT-updated tuples
* Fix multiple bugs in GiST index page split processing
* Fix possible buffer overrun in tsvector_concat()
* Fix crash in xml_recv when processing a "standalone" parameter
* Make pg_options_to_table return NULL for an option with no value
* Avoid possibly accessing off the end of memory in "ANALYZE" and in
  SJIS-2004 encoding conversion
* Prevent intermittent hang in interactions of startup process with
  bgwriter process
* Fix race condition in relcache init file invalidation
* Fix memory leak at end of a GiST index scan
* Fix incorrect memory accounting (leading to possible memory bloat)
  in tuplestores supporting holdable cursors and plpgsql's RETURN
  NEXT command
* Fix performance problem when constructing a large, lossy bitmap
* Fix join selectivity estimation for unique columns
* Fix nested PlaceHolderVar expressions that appear only in
  sub-select target lists
* Allow nested EXISTS queries to be optimized properly
* Fix array- and path-creating functions to ensure padding bytes are zeroes
* Fix "EXPLAIN" to handle gating Result nodes within inner-indexscan \ 
subplans
* Work around gcc 4.6.0 bug that breaks WAL replay
* Fix dump bug for VALUES in a view
* Disallow SELECT FOR UPDATE/SHARE on sequences
  This operation doesn't work as expected and can lead to failures.
* Fix "VACUUM" so that it always updates pg_class.reltuples/relpages
* more...