Re: Hot Standby and DROP DATABASE

On Saturday 06 February 2010 17:32:43 Andres Freund wrote:
> On Saturday 06 February 2010 02:25:33 Tatsuo Ishii wrote:
> > Hi,
> > 
> > While testing Hot Standby, I have encountered strange behavior with
> > DROP DATABASE command.
> > 
> > 1) connect to "test" database at standby via psql
> > 2) issue DROP DATABASE test command to primary
> > 3) session #1 works fine
> > 4) close session #1
> > 5) "test" database dropped on standby
> > 
> > Fromt the manual:
> >  Running DROP DATABASE, ALTER DATABASE ... SET TABLESPACE, or ALTER
> >  DATABASE ... RENAME on primary will generate a log message that will
> >  cause all users connected to that database on the standby to be
> >  forcibly disconnected. This action occurs immediately, whatever the
> >  setting of max_standby_delay.
> > 
> > So it seems at least the behavior is quite different from what the
> > docs stats. Am I missing something here?
> 
> Its a small bug/typo in standby.c:ResolveRecoveryConflictWithDatabase
> 
> The line:
>         CancelDBBackends(dbid, PROCSIG_RECOVERY_CONFLICT_TABLESPACE, true);
For the case it should not be clear, the reason that  
PROCSIG_RECOVERY_CONFLICT_TABLESPACE did not kill the session is that 
currently all tablespace conflicts are valid only inside a transaction, so when 
receiving the recovery conflict checks whether its not inside a transaction 
block "anymore" and continues happily.

Andres