Re: Update Statistics Plan for IDS 7.31

From: "Adam Bradley" <Adam.Bradley@ahmg.com.au> > >2. Run the "UPDATE STATISTICS HIGH" command with "DISTRIBUTIONS ONLY" for >all columns that head an index.This accuracy will give the optimizer the >best data about an index's selectivity. AFAIK: If you have two indexes index1 on table (a, b, c) index2 on table (a, b, d) You should use USHDO on columns a and b. ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

On Tue, 19 Oct 1999 08:42:48 BST, "Obnoxio The Clown" <obnoxio@hotmail.com> wrote: > >From: "Adam Bradley" <Adam.Bradley@ahmg.com.au> >> >>2. Run the "UPDATE STATISTICS HIGH" command with "DISTRIBUTIONS ONLY" for >>all columns that head an index.This accuracy will give the optimizer the >>best data about an index's selectivity. > >AFAIK: >If you have two indexes > >index1 on table (a, b, c) >index2 on table (a, b, d) > >You should use USHDO on columns a and b. If these are the only indexes on the table, update medium on b and all other columns distributions only, update high on a distributions only, update high on c distributions only, #not neccessary, but suggested update high on d distributions only, # same comment as above update low on (a,b,c) update low on (a,b,d) which is what either his or my update stats utility will do, both available at http://www.iiug.org Cheers, Douglas Wilson