Re: WIP: multivariate statistics / proof of concept

Tomas Vondra <tomas.vondra@2ndquadrant.com>

From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
Cc: pgsql-hackers@postgresql.org
Date: 2015-03-20T21:17:04Z
Lists: pgsql-hackers
Hello,

On 20.3.2015 09:33, Kyotaro HORIGUCHI wrote:
> Hello,
> 
> 
> Patch 0001 needs changes for OIDs since my patch was
> committed. The attached is compatible with current master.

Thanks. I plan to submit a new version of the patch in a few days, with
significant progress in various directions. I'll have to rebase to
current master before submitting the new version anyway (which includes
fixing duplicate OIDs).

> And I tried this like this, and got the following error on
> analyze. But unfortunately I don't have enough time to
> investigate it now.
> 
> postgres=# create table t1 (a int, b int, c int);
> insert into t1 (select a/ 10000, a / 10000, a / 10000 from
> generate_series(0, 99999) a);
> postgres=# analyze t1;
> ERROR:  invalid memory alloc request size 1485176862

Interesting - particularly because this does not involve any
multivariate stats. I can't reproduce it with the current version of the
patch, so either it's unrelated, or I've fixed it since posting the last
version.

regards

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


Commits

  1. Collect and use multi-column dependency stats

  2. Implement SortSupport for macaddr data type

  3. Implement multivariate n-distinct coefficients

  4. Generate fmgr prototypes automatically