Re: Reverse Key Index

On 26.02.2015 13:37, Heikki Linnakangas wrote:
> On 02/26/2015 12:31 AM, Josh Berkus wrote:
>> On 02/14/2015 10:35 AM, Sven R. Kunze wrote:
>>> Thanks for the immediate reply.
>>>
>>> I understand the use case is quite limited.
>>>
>>> On the other hand, I see potential when it comes to applications which
>>> use PostgreSQL. There, programmers would have to change a lot of 
>>> code to
>>> tweak existing (and more importantly working) queries to 
>>> hash/reverse an
>>> id column first. Using ORMs would make this change even more painful 
>>> and
>>> maybe even impossible.
>>>
>>> When reading
>>> https://richardfoote.wordpress.com/2008/01/14/introduction-to-reverse-key-indexes-part-i/ 
>>>
>>> carefully, it also seems to work with index scan partially in case of
>>> equality comparisons.
>>
>> Seems like a good use for SP-GiST.  Go for it!
>
> A b-tree opclass that just compares from right-to-left would work just
> as well, and perform better.
>
> - Heikki
>


Thanks for the hint. That also sounds easy to implement.

Regards,

-- 
Sven R. Kunze
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