On 05/11/12 02:47, Greg Sabino Mullane wrote:
Also by the time an application does execute some SQL, the the
connection/node/server/network could have dropped and so the application
'will have to check & recover from write failures at that point anyway."
This is a bit of a red herring. You could say that about any database action,
anytime ever. I personally think a simple select is better than relying
on a low-level library call, as it does a more complete end-to-end check
that is almost certainly closer to what the caller is going to use the
connection for.
I rather strongly disagree. It is possible to do useful work over a
connection
in situations when a 'simple select' is not possible. My production
Oracle database is protected by a physical standby database. This
database is, in Oracle terms, mounted but not open. A user with the SYSADMIN
privilege can connect to the database. It is possible use virtual views to
monitor the database and ALTER SYSTEM commands to change its state. However
it is not possible to select from any table. SELECT 1 FROM DUAL will fail.
I would like to see $dbh->ping to continue to return a true values in cases
like this.
--
Charles Jardine - Computing Service, University of Cambridge
c...@cam.ac.uk Tel: +44 1223 334506, Fax: +44 1223 334679
