Postgres from version 8.3 has feature which would make it much faster as a Bayes store or AWL store in SpamAssassin. It can turn off synchronous commits for non-critical transactions.

This feature will make saving data to a database much faster, say 2 orders of magnitude faster on ordinary hard drives, as commits would not need to wait for fsync. This would make it comparable to NoSQL databases but much safer.

This is safe setting - there's no risk of database corruption. In case of a power failure some transactions from the last 0.6s (3 * default wal_writer_delay setting) can be lost. But it does not matter at all for bayes or AWL database.

Please add something like this to sub _connect_db in lib/Mail/SpamAssassin/BayesStore/PgSQL.pm:

if ( $dbh->{pg_server_version} >= 80300 ) {
  $dbh->do('SET synchronous_commit=off')
}


As a workaround man can set "synchronous_commit=off" in postgresql.conf, but it would affect all Postgres databases. And it is somewhat advanced.

Is there a standard benchmark for bayes stores to run?