pg_reorg can re-organize tables on a postgres database without any locks so that you can retrieve or update rows in tables being reorganized. The module is developed to be a better alternative of CLUSTER and VACUUM FULL.
The pg_reorg project is a PostgreSQL Community project that is a part of the pgFoundry.
The pgFoundry page for the project is at http://pgfoundry.org/projects/reorg, where you can find downloads, documentation, bug reports, mailing lists, and a whole lot more.
