BTW, I think you should use -C option with pgbench for this kind of
testing. -C establishes connection for each transaction, which is
pretty much similar to the real world application which do not use
connection pooling. You will be supprised how PostgreSQL connection
overhead is large.
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp