MVSFORUMS.com

shalini

Can two primary keys can share the same index or not.

kolusu · Posted: Wed Jun 22, 2005 7:55 am Post subject:

Shalini,

I am not sure as to what you mean by two primary keys as A table can have only one primary key, and the columns of a primary key cannot contain null values.

Hope this helps...

Cheers

kolusu
_________________
Kolusu
www.linkedin.com/in/kolusu

shalini · Posted: Fri Jun 24, 2005 9:43 am Post subject:

hi kolusu
i mean to say composite key
create table t1 (empid int not null,ename char(10),eno int not null
composite key(empid,eno)) ;

The structure of the table is in above format , is one index is enough for two keys.
_________________
hello, i am a student ... currently prusing the
mainframe course in the institute

kolusu · Posted: Fri Jun 24, 2005 10:06 am Post subject:

Shalini,

An INDEX can have more than one column.

Hope this helps...

Cheers

kolusu
_________________
Kolusu
www.linkedin.com/in/kolusu

schintala · Posted: Fri Jun 24, 2005 1:29 pm Post subject:

Hi,
Since your table had composite key that means you already an index combination of those columns. Additionally you can have indiviual indexes on each of these columns that depends on your application. But it it not a good idea to have more indexes as it consumes lot of disk space and your query performace will be slower for any insert or undate functions.