Re: system views for walsender activity

Magnus Hagander <magnus@hagander.net>

From: Magnus Hagander <magnus@hagander.net>
To: Itagaki Takahiro <itagaki.takahiro@gmail.com>
Cc: Takahiro Itagaki <itagaki.takahiro@oss.ntt.co.jp>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2010-12-28T13:17:08Z
Lists: pgsql-hackers
On Tue, Dec 28, 2010 at 14:14, Itagaki Takahiro
<itagaki.takahiro@gmail.com> wrote:
> On Tue, Dec 28, 2010 at 21:46, Magnus Hagander <magnus@hagander.net> wrote:
>>> Unfortunately, 2 also requires initdb because pg_stat_activity will
>>> use LEFT JOIN instead of normal JOIN not to hide rows with databaseid = 0.
>>> All of them are items for 9.1.
>>
>> Did this one end up on the floor?
>>
>> We definitely need the very basic level for 9.1, and we can always
>> improve on it later :-) Do you want to keep working on it, or do you
>> want me to pick it up?
>
> OK, I'll work for it.

Great.


>> I'm not sure it makes much sense to add walsenders to pg_stat_activity
>> - a lot of the fields would no longer make any sense (statement start?
>> query start?) - I think we're better off with a separate view for
>> pg_stat_walsender. It would then only need the columns for procpid,
>> usesysid, usename, client_addr, client_port, and the WALsender
>> specific fields.
>
> +1 for the separate view. "backend_start" (or replication_start?)
> might be also reasonable.

Yeah, agreed. backend_start is probably the best one -
replication_start may be considered conceptually different if the
connection was dropped and reconnected. backend_start is more
explicit.

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