Re: system views for walsender activity

On Sun, Jan 9, 2011 at 15:53, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> On Sun, 2011-01-09 at 12:52 +0100, Magnus Hagander wrote:
>
>> One thing I noticed is that it gives an interesting property to my
>> patch for streaming base backups - they now show up in
>> pg_stat_replication, with a streaming location of 0/0.
>>
>> If the view is named pg_stat_replication, we probably want to filter
>> that out somehow. But then, do we want a separate view listing the
>> walsenders that are busy sending base backups?
>>
>> For that matter, do we want an indication that separates a walsender
>> not sending data from one sending that happens to be at location 0/0?
>> Most will leave 0/0 really quickly, but a walsender can be idle (not
>> received a command yet), or it can be running IDENTIFY_SYSTEM for
>> example.
>
> I think we need a status enum. ('BACKUP', 'CATCHUP', 'STREAM') for the 3
> phases of replication.

That seems reasonable. But if we keep BACKUP in there, should we
really have it called pg_stat_replication? (yeah, I know, I'm not
giving up :P)

(You'd need a 4th mode for WAITING or so, to indicate it's waiting for
a command)

--
 Magnus Hagander
 Me: http://www.hagander.net/
 Work: http://www.redpill-linpro.com/