Re: Are there tuning parameters that don't take effect immediately?

On Fri, Jun 12, 2015 at 4:52 PM, David G. Johnston <
david(dot)g(dot)johnston(at)gmail(dot)com> wrote:

> On Fri, Jun 12, 2015 at 4:37 PM, Michael Nolan <htfoot(at)gmail(dot)com> wrote:
>
>> The only thing I can come up that's happened since last night was that we
>> ran the nightly vacuum analyze on that database, but I did not change the
>> statistics target.
>>
>
>
> ​The answer to your question is no, parameters changes are worse would
> take effect after a reboot - though most are used on the very next query
> that runs.
>
> The vacuum would indeed likely account for the gains - there being
> significantly fewer ​dead/invisible rows to have to scan over and discard
> while retrieving the live rows that fulfill your query.
>
> David J.
>
>
I wouldn't have said there was much activity in those tables since the
previous day's vacuum, maybe a couple hundred rows changed or added in a
table that has nearly 900,000 rows, and the other tables involved probably
even less than that. There may be one table with more activity, perhaps
20,000 row updates and maybe a few dozen new rows in a table that has
400,000 rows. Maybe I need to manually analyze that table more often?

Vacuum analyze verbose generate way too much output, is there a way to get
some more straight forward numbers from an analyze?

I'm definitely not complaining about the improvement, I'm just trying to
get a handle on what really caused it and whether I can improve it even
further.
--
Mike Nolan