Re: Performance impact of log streaming replication

On 21/04/2010 5:15 AM, Andy wrote:
> What is the expected performance impact of the log streaming replication in 9.0?
>
> In the past I've used the log shipping replication of MySQL and it caused the performance of the master to drop by almost 50%. Just wondered if Postgresql's replication is expected to behave similarly.

Pg already writes the logs required as part of normal operation. Most
likely that performance drop with MySQL was due to the extra disk I/O of
logging activity, which you shouldn't see with Pg.

All streaming replication adds in performance terms should be some
network I/O and the need to keep those logs around until the slave has
received them.

--
Craig Ringer