Re: Add pgstathashindex() to get hash index table statistics.

On Thu, Apr 06, 2017 at 10:45:26AM +0530, Ashutosh Sharma wrote:
> >> Based on the earlier discussions, I have prepared a patch that would
> >> allow pgstathashindex() to show the number of unused pages in hash
> >> index. Please find the attached patch for the same. Thanks.
> >
> > My idea is that we shouldn't end up with both a zero_pages column and
> > an unused_pages column. Instead, we should end up with just an
> > unused_pages column, which will include both pages that are all-zeroes
> > and pages that have a valid special space marked as LH_UNUSED.
> >
> > Also, I don't see why it's correct to test PageIsEmpty() here instead
> > of just testing the page type as we do in pageinspect.
> >
> > Attached is a revised patch that shows what I have in mind; please
> > review. Along the way I made the code for examining the page type
> > more similar to what pageinspect does, because I see no reason for
> > those things to be different, and I think the pageinspect code is
> > better.
>
> I have reviewed the patch and it looks good to me. Also, the idea of
> including both zero and unused pages in a single 'unused' column looks
> better. Thanks.

[Action required within three days. This is a generic notification.]

The above-described topic is currently a PostgreSQL 10 open item. Robert,
since you committed the patch believed to have created it, you own this open
item. If some other commit is more relevant or if this does not belong as a
v10 open item, please let us know. Otherwise, please observe the policy on
open item ownership[1] and send a status update within three calendar days of
this message. Include a date for your subsequent status update. Testers may
discover new open items at any time, and I want to plan to get them all fixed
well in advance of shipping v10. Consequently, I will appreciate your efforts
toward speedy resolution. Thanks.

[1] https://www.postgresql.org/message-id/20170404140717.GA2675809%40tornado.leadboat.com