At 16:00 +0300 on 28/06/1999, Chris Bitmead wrote:
> Why do multi-field indexes? Umm. How about to avoid doing a sequential
> scan? If your query depends on multiple fields then once you've found
> the set based on the first index you would have to sequential scan that
> subset based on the second condition, unless you have a multi-field
> index.
Well, I may be wrong, but I seem to recall reading in one of these mailing
lists once that there is no real difference performance-wise between
multiple-field indices and single-field indices on same columns. There was
a bit of overhead. I think Vadim should know the answer to this question.
Herouth
--
Herouth Maoz, Internet developer.
Open University of Israel - Telem project
http://telem.openu.ac.il/~herutma