Descending Sort on index

[Trevor Best]

I have a unique index based on the following columns:
ProjectID (int)
MaterialCatalogID (int)

Material catalogues are pretty much static but projects are dynamic and
people are most likely to be working on the latest project so would
using a descending sort on the ProjectID in the index gain any
performance?

[Simon Hayes]

You'll probably have to give some more details of what your data looks
like, what your most frequent queries and data modifications are etc.
But changing the order of the index is probably only really useful when
you have a lot of queries which return results in that particular
order. You could always try it out on a test server, of course.

Simon

[Gert-Jan Strik]

An index can be traversed both ascending and descending. This means that
changing the index order (in the index definition) is never useful for
single column indexes.

If you have compound indexes, then the order can influence performance
of some very specific queries. Generally I would not worry about the
index order.

Gert-Jan
Trevor Best wrote:

I have a unique index based on the following columns:
ProjectID (int)
MaterialCatalogID (int)

Material catalogues are pretty much static but projects are dynamic and
people are most likely to be working on the latest project so would
using a descending sort on the ProjectID in the index gain any
performance?