Re: system views for walsender activity

On 18/06/10 13:41, Simon Riggs wrote:
> On Fri, 2010-06-18 at 11:33 +0900, Takahiro Itagaki wrote:
>
>> 1. Add another system view for walsenders, ex. "pg_stat_replication".
>> It would show pid, remote host, and sent location for each walsender.
>
> I prefer this option. I consider it an omission that we should correct.
>
> Not sure I understand why you block up access to the WALSendPtr and then
> propose re-accessing it in text form a few days later. Whatever else you
> do you should revoke the commit that did that.

Are you referring to the dead extern declaration of
GetOldestWALSendPointer()? That was indeed dead, the function itself was
already #ifdeffed out. If we go with the pg_state_replication view as
suggested above, it would've been useless anyway because it returns only
one value, not one for each walsender.

Let's discuss what the best possible user interface for the information
would be first, and then decide if we need/want to force an initdb for
that. We have pg_upgrade now, that makes initdb less painful, and if
it's just a new view it might be possible to just add a note in the
release notes that you'll have to run the CREATE VIEW manually if upgrading.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com