Обсуждение: Fwd: consecutive analyze calls with different column lists.

From: David Johnston <polobo@yahoo.com>
Date: December 19, 2011 8:09:36 EST
To: Marc Mamin <M.Mamin@intershop.de>
Subject: Re: [GENERAL] consecutive analyze calls with different column lists.

On Dec 19, 2011, at 8:04, "Marc Mamin" <M.Mamin@intershop.de> wrote:

Hello,

If I call analyze 2 times, e.g.

  analyze mytable (column_a, column_b);

  analyze mytable (column_a, column_c);

 

then I will loose statisics on column_b.

correct ?

many thanks,

Marc Mamin

 

Good question though my default assumption is that the statistics from the first call would remain; otherwise the single column form of analyze becomes pretty useless.

In other words, it is impossible for a column to have no statistics, only old ones.

David J.