Re: Hash Indexes

Amit Kapila <amit.kapila16@gmail.com>

From: Amit Kapila <amit.kapila16@gmail.com>

To: Robert Haas <robertmhaas@gmail.com>

Cc: Jeff Janes <jeff.janes@gmail.com>, Jesper Pedersen <jesper.pedersen@redhat.com>, Mithun Cy <mithun.cy@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2016-09-20T13:02:21Z

Lists: pgsql-hackers

Attachments

concurrent_hash_index_v8.patch (application/octet-stream) patch v8

On Fri, Sep 16, 2016 at 11:22 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> I do want to work on it, but it is always possible that due to some
> other work this might get delayed.  Also, I think there is always a
> chance that while doing that work, we face some problem due to which
> we might not be able to use that optimization.  So I will go with your
> suggestion of removing hashscan.c and it's usage for now and then if
> required we will pull it back.  If nobody else thinks otherwise, I
> will update this in next patch version.
>

In the attached patch, I have removed the support of hashscans.  I
think it might improve performance by few percentage (especially for
single row fetch transactions) as we have registration and destroy of
hashscans.

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

Commits

Remove _hash_wrtbuf() in favor of calling MarkBufferDirty().
- 25216c989384 10.0 landed
Fix race introduced by 6d46f4783efe457f74816a75173eb23ed8930020.
- 2f4193c3509a 10.0 cited
Improve hash index bucket split behavior.
- 6d46f4783efe 10.0 landed
Reduce pinning and buffer content locking for btree scans.
- 2ed5b87f96d4 9.5.0 cited