Re: WAL recovery, stop and resume recovery?

David Wall <d(dot)wall(at)computer(dot)org> writes:
> Is it allowable to have a backup database in recovery mode, then stop
> recovery (in this case, by putting the trigger file in place to stop
> pg_standby), check out that the backup db appears up to date, stop the
> now active backup db, and then restart it in recover mode again to have
> it resume its backup role?

No. Once you've done any transactions in the backup DB, its transaction
history has diverged from the master and you can't resume tracking the
master. It shouldn't even let you try --- what shenanigans did you pull
to force it back into recovery mode?

There's some work being done on allowing read-only queries against an
in-recovery database, which I think would satisfy your desire to see if
the backup were sane or not. But I wouldn't bet money on that getting
into the system anytime soon. It's definitely not something you can
cobble up from spare parts.

regards, tom lane