Re: warm-standby errors

On Mon, 2009-05-11 at 13:50 -0400, sramirez wrote:

> Short of copying the data files elsewhere and doing a row-level
> comparison of the data, is there any way I can check to see if there is
> actual corruption in the warm standby server?

Right now, Warm Standby has same functionality as equivalent Oracle
feature - i.e. no way to confirm absence of corruption. However, WAL
records contain CRC checks that ensure the transferred data is correct,
which is more than most other replication techniques posess. Hot Standby
will allow access to data blocks to allow them to be read and checked,
though that is also possible with an external utility to some extent.

It probably isn't practical with any replication system to confirm the
exact contents of both nodes while replication is running at reasonable
speed. Some heuristics may be possible.

Do you have anything in mind, other than "detect corruption"?

> How can I prevent this
> error from occurring ?

You haven't shown us the error, just what happens afterwards.

--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Training, Services and Support