Postgres Pro
Downloads
Home   >   mailing lists

Re: Why is n_distinct always -1 for range types? - Mailing list pgsql-performance

From Josh Berkus
Subject Re: Why is n_distinct always -1 for range types?
Date
Msg-id 52431D6B.30302@agliodbs.com
Whole thread Raw
In response to Why is n_distinct always -1 for range types?  (Josh Berkus <josh@agliodbs.com>)
List pgsql-performance
Tree view 
On 09/19/2013 01:47 PM, Josh Berkus wrote:
> Test:
>
> 1. create a table with a range type column.
> 2. insert 1000 identical values into that column.
> 3. analyze
> 4. n-distinct will still be listed as -1 (unique) for the column.
>
> Why?
>

Anyone?

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com

pgsql-performance by date:

Previous
From: Claudio Freire
Date:
Subject: Re: Slow plan for MAX/MIN or LIMIT 1?
Next
From: Josh Berkus
Date:
Subject: Re: Planner performance extremely affected by an hanging transaction (20-30 times)?