Обсуждение: Multiple Indexes

Hi Group,

Lets say table a has fields: id serial, name varchar(20) not null, and 
somedata int not null.

I'll be doing lots of queries on this table so I'll want to define and 
index. ( or two? ).

Some queries will only look up the name.  Others will look up the name 
depending on somedata.

If I were to define and index like this:

1) create index i on sometable ( name, somedata );

and another one like this:

2) create index i2 on sometable ( name );

Would that be better than defining only the first index?

What I am asking is:

Should I have an index devoted to just the name field, or 
would that first index work just fine?  I know that more indexes
means slower time on inserts.

Any suggestions appreciated.

-Dennis