Re: [POC] A better way to expand hash indexes.

Mithun Cy <mithun.cy@enterprisedb.com>

From: Mithun Cy <mithun.cy@enterprisedb.com>
To: David Steele <david@pgmasters.net>
Cc: Amit Kapila <amit.kapila16@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-03-18T17:29:21Z
Lists: pgsql-hackers

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On Thu, Mar 16, 2017 at 10:55 PM, David Steele <david@pgmasters.net> wrote:
> It does apply with fuzz on 2b32ac2, so it looks like c11453c and
> subsequent commits are the cause.  They represent a fairly substantial
> change to hash indexes by introducing WAL logging so I think you should
> reevaluate your patches to be sure they still function as expected.

Thanks, David here is the new improved patch I have also corrected the
pageinspect's test output. Also, added notes in README regarding the
new way of adding bucket pages efficiently in hash index. I also did
some more tests pgbench read only and read write;
There is no performance impact due to the patch. The growth of index
size has become much efficient as the numbers posted in the initial
proposal mail.

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

Commits

  1. Fix formula in _hash_spareindex.

  2. Expand hash indexes more gradually.

  3. Change hash indexes to store only the hash code rather than the whole indexed