Re: Help HASH clusters oracle 7

From: Mark Malakanov <markmal_at_sprint.ca>
Date: Wed, 30 Jun 1999 10:48:50 -0300
Message-ID: <34qe3.168908$r_1.40403114@newscontent-02.sprint.ca>

To make good hash cluster you need to choose the column with big selectivity.
This column will be used later as assess key to table. Usualy the best are ID columns. This are unique.

Sample:
If you have table Streets

ID Name
------ -----------

1      Abbey
2      Aglington

.....
20000000 Yonge

The good hash key will ID

create cluster Streets_HC (ID number)
size 40 -- set average size of full row (all colums) in bytes or a little bit more.
hashkeys 200001000 --a little bit more
hash is ID;

• add table to cluster create table Streets (id number, Name char(30)) cluster Streets_HC (ID);

Regards,
Mark

Seigmund Akinwande Johnson <asjohns_at_midway.uchicago.edu> wrote in message news:FE3ywG.DwC_at_midway.uchicago.edu...
> All:
>
> Who has ever worked with this and what are the issues to consider,
> I have a 20 Million static record table, that requires fast access
> Any help would be fine
>
> --
> Developer Preserve Project
> BSDIS
> 773-834-2652
>
>
Received on Wed Jun 30 1999 - 08:48:50 CDT