Re: Hash index todo list item

On Mon, Sep 03, 2007 at 05:20:34PM -0700, Ben Tilly wrote:
> 
> That raises a very random thought.  One of the nicer features of
> Oracle is the ability to have function-based indexes.  So you could
> index, say, trim(lower(person.name)).  There are a *lot* of practical
> situations where that comes in handy.  The best workaround that I can
> think of for not having that is to have a column defined to hold the
> result of the function, maintain that column with a trigger, then
> index that column.  Which works, but is inelegant.  (It also requires
> storing completely redundant data.)
> 
> Is there any prospect of postgres aquiring that functionality?
> 
> Ben
> 
I believe that PostgreSQL already supports functional indexes. In fact,
one suggestion to address the egregiously poor performance of the current
hash index was to replace it with a functional index.

Regards,
Ken