PostgreSQL is used by thousands of organisations worldwide and is often regarded as the "enterprise grade" open source database compared with the more popular MySQL.

Notable enhancements in version 8.4 include parallel database restore for speeding up recovery from backup (by up to eight times); per-column permissions for more granular control of sensitive data; and per-database collation support to make PostgreSQL more useful in multi-lingual environments.

PostgreSQL users include IMAN international, All Homes and shopping centre giant Westfield.

Also new in 8.4 is in-place upgrades through pg_migrator (beta) to enable upgrades from 8.3 to 8.4 without "extensive" downtime and new query monitoring tools to give administrators more insight into query activity.

Kevin Grittner, database administrator for the Wisconsin courts system, said the new release boosts application performance.

"Version 8.4 has added several optimisations, such as semi-joins and anti-joins, which provide dramatic improvement in the run time of some of our most demanding queries," Grittner said.

According to the developers, version 8.4 makes data analysis easier through the advanced ANSI SQL2003 features of windowing functions, common table expressions and recursive joins.

Jeffrey Webster, CTO of ZooLoo.com, said: "We've used PostgreSQL for seven years now, and we're really looking forward to many of the features in 8.4, particularly column permissions, per-database locale, partial matches for GIN indexes and user defined exceptions. PostgreSQL has allowed us to grow without sacrificing data integrity."

The OpenStreetMap project is also a PostgreSQL user.

OpenStreetMap system administrator Tom Hughes said when the mapping service was planning the new version of its API, it needed a world-class database that runs well at the scale it needs.

PostgreSQL 8.4 can be downloaded from www.postgresql.org and the full list of 8.4 features is also online.