On 04.10.2010 17:22, Fujii Masao wrote:
> If we make all the transactions wait until specified standbys have
> connected to the master, how do we take a base backup from the
> master for those standbys? We seem to be unable to do that because
> pg_start_backup also waits forever. Is this right?
Hmm, pg_start_backup() writes WAL, but it doesn't commit. Only a commit
needs to wait for acknowledgment from the standby, so 'wait forever'
behavior doesn't necessarily mean that you can't take a base backup. If
you run it outside a transaction you get an implicit commit, though,
which will wait, so you might need to do something odd like "begin;
select pg_start_backup(); rollback".
But I agree with Tom that as long as it's possible to change the
configuration on the fly, it's not a show-stopper if you can't take a
new base backup while the standby is disconnected.
-- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com