Failover pair with a primary and standby. The primary streams write-ahead log records to standby as they're generated. Some script gaffer-tape to watch for primary failure and fail over. I think we haven't ever yet actually had to invoke this though :-)

This was all cobbled together following the docs. There are almost certainly better ways to do everything we've done so far.

The Postgres is just 9.3 out of the Ubuntu 14.04 repo. Oracle was STUPENDOUS overkill for what it was actually being used for, but MySQL wasn't up to the job.

The heavy lifting for the conversion is done using ora2pg http://ora2pg.darold.net/ Then there's a pile of faff and twiddling and unit tests and so forth. See also https://wiki.postgresql.org/wiki/Oracle_to_Postgres_Conversi...