| From: | Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> |
|---|---|
| To: | Greg Stark <stark(at)mit(dot)edu> |
| Cc: | Claudio Freire <klaussfreire(at)gmail(dot)com>, Leonardo Francalanci <m_lists(at)yahoo(dot)it>, PostgreSQL-Dev <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Fast insertion indexes: why no developments |
| Date: | 2013-11-06 00:59:04 |
| Message-ID: | 20131106005904.GJ5809@eldon.alvh.no-ip.org |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Greg Stark escribió:
> I think minmax indexes are more akin to bitmap indexes. They will be very
> effective for columns with low-cardinality, especially for columns that are
> very clustered. In the extreme if all the values in some regions of the
> table are the same then minmax indexes would be optimal. I wouldn't expect
> them to be very effective for a highly selective column that isn't well
> clustered.
I think clustering is more important than cardinality. I mean you can
have a very useful minmax index on a float column, on which maybe there
are no two identical values.
I certainly don't think minmax indexes will solve all indexing problems.
In the end, they're just one more tool in your DBA toolbox.
--
Álvaro Herrera http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
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