Re: Displaying accumulated autovacuum cost

On Thu, Aug 18, 2011 at 03:23, Greg Smith <greg(at)2ndquadrant(dot)com> wrote:
> On 08/17/2011 07:42 PM, Euler Taveira de Oliveira wrote:
>>
>> I don't like exposing this information only on title processes. It would
>> be difficult for client apps (for example, PGAdmin) to track this kind of
>> information and it is restricted to local access. I'm not objecting to
>> display this information in process title; I'm just saying that that
>> information should be exposed in  functions (say
>> pg_stat_get_vacuum_[hit|miss|dirty]) too.
>
> I tend to build the simplest possible thing that is useful enough to work.
>  The data is getting stored and shown now, where it wasn't before.  If it's
> possible to expose that in additional ways later too, great.  The big step
> up for this information is to go from "unobtainable" to "obtainable".  I'd
> prefer not to add a quest for "easily obtainable" to the requirements until
> that big jump is made, for fear it will cause nothing to get delivered.

By only putting it in the ps display, you exclude all the users who
don't have an easy way to look at that information. The big group
there is Windows, but it's not necessarily easy on all other platforms
as well, afaik. And possibliy even more importantly, it makes it
impossible to view it from tools like pgadmin. I think it's definitely
worthwhile to add support to view it through the stats collector as
well from the beginnig. The question there is if it's enough to just
show it in the current_query (kind of like it's done in the ps
output), or if we want a completely separate view with this info.

Also, unrelated to that, wouldn't this information be interesting for
non-autovacuum queries as well?

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