On 6/15/07, Craig James <craig_james@xxxxxxxxxxxxxx> wrote: [snip]
Is this a good summary of the status of replication? Have I missed any important solutions or mischaracterized anything?
* Mammoth Replicator, commercial. * Continuent uni/cluster, commercial (http://www.continuent.com/index.php?option=com_content&task=view&id=212&Itemid=169). * pgpool-II. Supports load-balancing and replication by implementing a proxy that duplicates all updates to all slaves. It can partition data by doing this, and it can semi-intelligently route queries to the appropriate servers. * Cybertec. This is a commercial packaging of PGCluster-II from an Austrian company. * Greenplum Database (formerly Bizgres MPP), commercial. Not so much a replication solution as a way to parallelize queries, and targeted at the data warehousing crowd. Similar to ExtenDB, but tightly integrated with PostgreSQL. * DRDB (http://www.drbd.org/), a device driver that replicates disk blocks to other nodes. This works for failover only, not for scaling reads. Easy migration of devices if combined with an NFS export. * Skytools (https://developer.skype.com/SkypeGarage/DbProjects/SkyTools), a collection of replication tools from the Skype people. Purports to be simpler to use than Slony. Lastly, and perhaps most promisingly, there's the Google Summer of Code effort by Florian Pflug (http://code.google.com/soc/postgres/appinfo.html?csaid=6545828A8197EBC6) to implement true log-based replication, where PostgreSQL's transaction logs are used to keep live slave servers up to date with a master. In theory, such a system would be extremely simple to set up and use, especially since it should, as far as I can see, also transparently replicate the schema for you. Alexander.
