Re: Index usage

On Fri, 8 Jun 2001, Subra Radhakrishnan wrote:

> Hi All,
>
> The index created by me is not being used while doing
> select. I found that out by using the EXPLAIN. For
> example:
>
> Table department has
> ----------------
> dept_num
> dept_desc
>
>
> Table 'employee' looks like this:
> --------------------------------
> emp_num primary key,
> emp_name,
> dept_num (this is by way of foreign key relation from
> department table)
>
> Now, I create an index on the employee table using
> 'dept_num' as the attribute. And when I run select
> which looks like:
>
> Explain Select * from employee where dept_num =
> 'Finance';
>
> It does not use the index and tells me that a
> Sequential scan will be done on the table employee.
>
> How do I fix this?

Have you run vacuum analyze, what's the full schema
(with types) and the explain output?