Re: unique index on function and column

Bruno Wolff III <bruno@wolff.to> writes:
> Is there a simple way to do something like the following:
> create unique index inst_u_app on inst (lower(host), psport);

> It looks like you can have an index on several columns, but not
> several functions.

The standard answer is to make a custom function that accepts all the
columns and produces a result you can index.

This is sort of an academic "an existence proof is good enough" answer,
but it *is* possible to get the results you want.  Making it more
convenient hasn't risen to the top of anyone's to-do list.
        regards, tom lane