Log Message:
Changes 8.4.5:
* Use a separate interpreter for each calling SQL userid in PL/Perl and PL/Tcl
* Prevent possible crashes in pg_get_expr() by disallowing it from being called
  with an argument that is not one of the system catalog columns it's intended
  to be used with
* Treat exit code 128 (ERROR_WAIT_NO_CHILDREN) as non-fatal on Windows
* Fix incorrect placement of placeholder evaluation
* Fix possible duplicate scans of UNION ALL member relations
* Fix "cannot handle unplanned sub-select" error
* Fix mishandling of whole-row Vars that reference a view or sub-select and
  appear within a nested sub-select
* Fix mishandling of cross-type IN comparisons
* Fix computation of "ANALYZE" statistics for tsvector columns
* Improve planner's estimate of memory used by array_agg(), string_agg(), and
  similar aggregate functions
* Fix failure to mark cached plans as transient
* Reduce PANIC to ERROR in some occasionally-reported btree failure cases, and
  provide additional detail in the resulting error messages
* Fix incorrect search logic for partial-match queries with GIN indexes
* Prevent show_session_authorization() from crashing within autovacuum
  processes
* Defend against functions returning setof record where not all the returned
  rows are actually of the same rowtype
* Fix possible corruption of pending trigger event lists during subtransaction
  rollback
* Fix possible failure when hashing a pass-by-reference function result
* Improve merge join's handling of NULLs in the join columns
* Take care to fsync the contents of lockfiles (both "postmaster.pid" \ 
and the
  socket lockfile) while writing them
* Avoid recursion while assigning XIDs to heavily-nested subtransactions
* Avoid holding open old WAL segments in the walwriter process
* Fix log_line_prefix's %i escape, which could produce junk early in backend
  startup
* Prevent misinterpretation of partially-specified relation options
  for TOAST tables
* Fix inheritance count tracking in "ALTER TABLE ... ADD CONSTRAINT"
* Fix possible data corruption in "ALTER TABLE ... SET TABLESPACE" when
  archiving is enabled
* Allow "CREATE DATABASE" and "ALTER DATABASE ... SET \ 
TABLESPACE" to be
  interrupted by query-cancel
* Improve "CREATE INDEX"'s checking of whether proposed index
  expressions are immutable
* Fix "REASSIGN OWNED" to handle operator classes and families
* Fix possible core dump when comparing two empty tsquery values
* Fix LIKE's handling of patterns containing % followed by _