In talking to developers, it appears that index-only scans will not be
implemented in Postgres 8.5 due to development time being spend on hot
standby and streaming replication. The current index-only scan status
is summarized here:
http://archives.postgresql.org/pgsql-hackers/2009-07/msg00675.php
--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +