Re: [HACKERS] multivariate statistics (v19)

On 01/03/2017 02:42 PM, Dilip Kumar wrote:
> On Tue, Dec 13, 2016 at 3:20 AM, Tomas Vondra
> <tomas.vondra@2ndquadrant.com> wrote:
>> attached is v21 of the patch series, rebased to current master (resolving
>> the duplicate OID and a few trivial merge conflicts), and also fixing some
>> of the issues you reported.
>
> I wanted to test the grouping estimation behaviour with TPCH, While
> testing I found some crash so I thought of reporting it.
>
> My setup detail:
> TPCH scale factor : 5
> Applied all the patch for 21 series, and ran below queries.
>
> postgres=# analyze part;
> ANALYZE
> postgres=# CREATE STATISTICS s2  WITH (ndistinct) on (p_brand, p_type,
> p_size) from part;
> CREATE STATISTICS
> postgres=# analyze part;
> server closed the connection unexpectedly
> This probably means the server terminated abnormally
> before or while processing the request.
> The connection to the server was lost. Attempting reset: Failed.
>
> I think it should be easily reproducible, in case it's not I can send
> call stack or core dump.
>

Thanks for the report. It was trivial to reproduce and it turned out to 
be a fairly simple bug. Will send a new version of the patch soon.

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services