Re: UUID index unused - Mailing list pgsql-general

From Adrian Klaver
Subject Re: UUID index unused
Date
Msg-id 545FBE28.80106@aklaver.com
Whole thread Raw
In response to UUID index unused  (Kevin Wooten <kdubb@me.com>)
List pgsql-general
On 11/09/2014 10:58 AM, Kevin Wooten wrote:
> I am assuming I am crazy and missing something completely obvious but I cannot get postgres (9.3.5) to use an index
ona UUID, ever. 
>
> The main table has a natural composite key (2 uuids and a timestamp) with which it always uses the timestamp as the
indexcondition and filters on the UUIDs.  This occurs when when we do a query for a specific item comparing all 3 key
columnswith equality.  Other tables that have a single UUID column index also fail to ever utilize any available
indices;querying for a specific UUID always results in a table scan for them. 
>
> Switching the UUID columns to text immediately solves the issues and index usage is as expected in all cases.
>
> After hours of fiddling I figured it was time to ask.  Any ideas?

The only thing I could after a quick search was this:

http://stackoverflow.com/questions/22720130/how-to-use-uuid-with-postgresql-gist-index-type

Sort of a hybrid approach.
>
> P.S.  Before it’s suggested… we have millions of independent devices generating the ids which drives our use of
UUIDs. Any thoughts of replacing them only result in us building something that’s basically a UUID to replace it. 
>
>
>


--
Adrian Klaver
adrian.klaver@aklaver.com


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