Re: Querying distinct values from a large table

On 1/30/07, Luke Lonergan <llonergan@greenplum.com> wrote:
>
> Not that it helps Igor, but we've implemented single pass sort/unique,
> grouping and limit optimizations and it speeds things up to a single
> seqscan
> over the data, from 2-5 times faster than a typical external sort.


Was that integrated back into PostgreSQL, or is that part of Greenplum's
offering?

I can't think of a way that indexing would help this situation given the
> required visibility check of each tuple.
>

I agree, using indexes as a "skinny" table is a whole other feature that
would be nice.


-- 
Chad
http://www.postgresqlforums.com/