Re: [HACKERS] pgsql 10: hash indexes testing - Mailing list pgsql-hackers

From Amit Kapila
Subject Re: [HACKERS] pgsql 10: hash indexes testing
Date
Msg-id CAA4eK1JvZD5uSqjq2zPaJXBa-g+8XfJJkkc2i=dqHtrhVRoT2Q@mail.gmail.com
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In response to Re: [HACKERS] pgsql 10: hash indexes testing  (AP <ap@zip.com.au>)
List pgsql-hackers
On Fri, Aug 11, 2017 at 5:01 AM, AP <ap@zip.com.au> wrote:
> On Thu, Aug 10, 2017 at 01:12:25PM -0400, Robert Haas wrote:
>> On Thu, Aug 10, 2017 at 6:41 AM, AP <ap@zip.com.au> wrote:
>> > The index is 135GB rather than 900GB (from memory/give or take).
>>
>> Whoa.  Big improvement.
>
>
> As an aside, btree for the above is around 2.5x bigger than hash v4 so
> chances are much better that a hash index will fit into ram which has
> its own benefits. :)
>

Yeah, that's exactly one of the benefit hash indexes can provide over
btree indexes.


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



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