Re: Save Hash Indexes - Mailing list pgsql-hackers

From Hannu Krosing
Subject Re: Save Hash Indexes
Date
Msg-id 5273EF5D.5060503@2ndQuadrant.com
Whole thread Raw
In response to Re: Save Hash Indexes  (Andres Freund <andres@2ndquadrant.com>)
List pgsql-hackers
On 11/01/2013 03:49 PM, Andres Freund wrote:
> On 2013-11-01 09:49:57 -0400, Tom Lane wrote:
>> Lastly: what real-world problem are we solving by kicking that code
>> to the curb?
> It makes hashed lookups much easier to use. Currently if you want
> indexed access over wide columns and equality is all you need you need
> to write rather awkward queries to make that happen in each query,
> something like:
> WHERE hash(column) = hash('value') AND column = 'value'.
>
> So some magic that hides having to do that would be nice, even it
> doesn't have O(log(n)) properties. 
Is'nt there a way to do this using a special operator class ?
> The interesting part is that the
> index gets much denser and smaller, and that the individual comparisons
> are much cheaper.
>
> Greetings,
>
> Andres Freund
>


-- 
Hannu Krosing
PostgreSQL Consultant
Performance, Scalability and High Availability
2ndQuadrant Nordic OÜ




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