Riak, a scalable and reliable data store, is available in Fedora 15.
Riak is a Dynamo-inspired key/value store, written in Erlang, that scales predictably and easily. Riak also simplifies development by giving developers the ability to quickly prototype, test, and deploy their applications.
A truly fault-tolerant system, Riak has no single point of failure. No machines are special or central in Riak, so developers and operations professionals can decide exactly how fault-tolerant they want and need their applications to be.
has been updated to version 5.5.8. Included are improved scalability and performance. From the release announcement: "Higher availability: New semi-synchronous replication and Replication Heart Beat improve failover speed and reliability."
This update includes increasing the shared library version number of libmysqlclient, so applications using that library will need to be recompiled.
- Built-in replication, based on log shipping, supports multiple read-only slave servers
- Easier database object permissions management
- Broadly enhanced stored procedure support
- More advanced reporting queries
- New trigger features
- Deferrable unique constraints
- Mass updates to unique keys are now possible without trickery
- Exclusion constraints
- New and enhanced security features
- New high-performance implementation of the LISTEN/NOTIFY feature
- New implementation of VACUUM FULL
- Multiple performance enhancements for specific types of queries, including elimination of unnecessary joins
- EXPLAIN enhancements
- hstore improvements
In addition, there is a new contrib module pg_upgrade to support in-place upgrades from 8.4 to 9.0. This means that you can upgrade from a Fedora 12 or later database without a database dump and restore. To do that, install the postgresql-upgrade package and run service postgresql upgrade as root. It's advisable to have a separate backup in case of trouble, but the actual database conversion requires only a few minutes with this approach.