Re: Proposal : For Auto-Prewarm.

On Fri, Jun 23, 2017 at 5:45 AM, Thom Brown <thom(at)linux(dot)com> wrote:

>
> I also think pg_prewarm.dump_interval should be renamed to
> pg_prewarm.autoprewarm_interval.

Thanks, I have changed it to pg_prewarm.autoprewarm_interval.

>>
>> * In the documentation, don't say "This is a SQL callable function
>> to....". This is a list of SQL-callable functions, so each thing in
>> the list is one. Just delete this from the beginning of each
>> sentence.

> One thing I couldn't quite make sense of is:
>
> "The autoprewarm process will start loading blocks recorded in
> $PGDATA/autoprewarm.blocks until there is a free buffer left in the
> buffer pool."
>
> Is this saying "until there is a single free buffer remaining in
> shared buffers"? I haven't corrected or clarified this as I don't
> understand it.

Sorry, that was a typo I wanted to say until there is no free buffer
left. Fixed in autoprewarm_16.patch.

>
> Also, I find it a bit messy that launch_autoprewarm_dump() doesn't
> detect an autoprewarm process already running. I'd want this to
> return NULL or an error if called for a 2nd time.

We log instead of error as we try to check only after launching the
worker and inside worker. One solution could be as similar to
autoprewam_dump_now(), the autoprewarm_start_worker() can init shared
memory and check if we can launch worker in backend itself. I will try
to fix same.

--
Thanks and Regards
Mithun C Y
EnterpriseDB: http://www.enterprisedb.com