On Fri, 10 Mar 2006, Martijn van Oosterhout wrote:
You don't describe the exact structure of your table nor the exact
declaraion of your function, but is it possible your function is marked
VOLATILE rather tha STABLE or IMMUTABLE?
Thanks for that hint - my function was not marked in any way, so I guess
it
got to be VOLATILE by default. I have just marked it as IMMUTABLE and it
now uses the index as expected, with a huge performance gain. I confess
that I was totally ignorant of the differences between these three types
of function.
Sorry I slightly messed up the cut/paste of my posting, I had been
experimenting with various versions of the same table and didn't quite get
the details consistent in what I posted.
Thanks also to Richard Huxton and Martin van Oosterhout who gave me the
same hint.
What an excellent support group this is.
--
Clive Page
Dept of Physics & Astronomy,
University of Leicester,
Leicester, LE1 7RH, U.K.
