Re: Problems with Binary Replication

On Sat, Mar 31, 2012 at 6:58 PM, Andreas <maps(dot)on(at)gmx(dot)net> wrote:

>
>
> Now what could one do to prevent those sequence gaps?
> There might be scenarios where it's important not to have gaps in the
> numbering even when one has to switch to the standby if there is a failiour
> on the master.
> E.g. numbers of invoices need to be gapless.
>
>
Then you may need to find some other way within your application to assign
invoice numbers, because sequences aren't GUARANTEED not to have gaps,
especially if there is a failure of the primary server that results in a
switch over to the standby server.

A transaction that is rolled back (such as due to an error) after the
nextval() function has been called will not roll back the sequence value,
for example.

You cannot issue a nextval() call on a standby server, because it is in
read-only mode.
--
MIke Nolan