Although the new asynchronous replication facility that ships with 9.0 ain’t released to the wide public yet, our hackers hero are already working on the synchronous version of it. A part of the facility is rather easy to design, we want something comparable to DRBD flexibility, but specific to our database world. So synchronous would either mean recv, fsync or apply, depending on what you need the standby to have already done when the master acknowledges the COMMIT.
There’s a big trend nowadays about using column storage as opposed to what PostgreSQL is doing, which would be row storage. The difference is that if you have the same column value in a lot of rows, you could get to a point where you have this value only once in the underlying storage file. That means high compression. Then you tweak the executor to be able to load this value only once, not once per row, and you win another huge source of data traffic (often enough, from disk).
It’s time for Skytools news again! First, we did improve documentation of current stable branch with hosting high level presentations and tutorials on the PostgreSQL wiki. Do check out the Londiste Tutorial, it seems that’s what people hesitating to try out londiste were missing the most. The other things people miss out a lot in current stable Skytools (version 2.1.9 currently) are cascading replication (which allows for switchover and failover) and DDL support.