Re: If an index is based on 3 columns will a query using two of the columns utilize the index?

[Michael Fuhr <mike@xxxxxxxx>]

On Mon, Sep 12, 2005 at 10:05:36AM -0400, Reid Thompson wrote:
> Alvaro Herrera wrote:
> > Note that if your example query used the columns (lname, dob),
> > the answer would be "no." 
>
> Why is that? In order to use an index, does the query have to utilize
> the 'first' element of the index?

In released versions of PostgreSQL, yes.  Version 8.1 will remove
that restriction.

-- 
Michael Fuhr

---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
       choose an index scan if your joining column's datatypes do not
       match