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

Mithun Cy <mithun.cy@enterprisedb.com>

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From: Mithun Cy <mithun.cy@enterprisedb.com>

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

Cc: David Steele <david@pgmasters.net>, pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2017-03-25T04:43:00Z

Lists: pgsql-hackers

Attachments

expand_hashbucket_efficiently_06_spares_2dimesion.patch (application/octet-stream) patch
expand_hashbucket_efficiently_06_spares_1dimension.patch (application/octet-stream) patch

On Tue, Mar 21, 2017 at 8:16 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> Sure, I was telling you based on that.  If you are implicitly treating
> it as 2-dimensional array, it might be easier to compute the array
>offsets.

I think calculating spares offset will not become anyway much simpler
we still need to calculate split group and split phase separately. I
have added a patch to show how a 2-dimensional spares code looks like
and where all we need changes.

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

Commits

Fix formula in _hash_spareindex.
- b38006ef6d1b 10.0 landed
Expand hash indexes more gradually.
- ea69a0dead51 10.0 landed
Change hash indexes to store only the hash code rather than the whole indexed
- 4adc2f72a4cc 8.4.0 cited