Subject Re: Primary/Foreign Key Constraints and Indexing - to do, or not to do
Author Adam
--- In, "Photios Loupis (4T)"
<loupisp@...> wrote:
> Please could someone advise whether it is necessary/advisable or not
> to create separate indices for each Primary or Foreign key contraint
> fields?

No, don't do it.

Primary Key, Foreign Key and Unique constraint fields automatically
create an ascending index in your database.

Adding another index:

* uses space (waste)
* requires time to maintain (more waste)
* can potentially confuse the optimiser

The only possible exception would be if you wanted a descending index
on such a field, that is OK. But otherwise you do not want to do that.