On Fri, Jul 08, 2005 at 12:08:41 -0400,
Ying Lu <ying_lu(at)cs(dot)concordia(dot)ca> wrote:
> Greetings,
>
> A question about creating index for the following expression.
>
> CREATE INDEX idx_t1 ON test (col1 || '-' || col2);
>
> May I know is it possible and how I may create index for the expression
> such as "col1 || '-' || col2" for a table please?
You have already received some answers to this specific question.
However, you might consider a different solution to the underlying
problem. You can make a multicolumn index that for many purposes would
be better than the above functional index.