Re: Hash Indexes

Amit Kapila <amit.kapila16@gmail.com>

From: Amit Kapila <amit.kapila16@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Jesper Pedersen <jesper.pedersen@redhat.com>, Jeff Janes <jeff.janes@gmail.com>, Mithun Cy <mithun.cy@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2016-12-01T05:43:51Z
Lists: pgsql-hackers
On Thu, Dec 1, 2016 at 2:18 AM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Wed, Nov 23, 2016 at 8:50 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>> [ new patch ]
>
> Committed with some further cosmetic changes.
>

Thank you very much.

> I think it would be worth testing this code with very long overflow
> chains by hacking the fill factor up to 1000
>

1000 is not a valid value for fill factor. Do you intend to say 100?

 or something of that
> sort, so that we get lots and lots of overflow pages before we start
> splitting.  I think that might find some bugs that aren't obvious
> right now because most buckets get split before they even have a
> single overflow bucket.
>
> Also, the deadlock hazards that we talked about upthread should
> probably be documented in the README somewhere, along with why we're
> OK with accepting those hazards.
>

That makes sense.  I will send a patch along that lines.



-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com


Commits

  1. Remove _hash_wrtbuf() in favor of calling MarkBufferDirty().

  2. Fix race introduced by 6d46f4783efe457f74816a75173eb23ed8930020.

  3. Improve hash index bucket split behavior.

  4. Reduce pinning and buffer content locking for btree scans.