[plug] auto-increment in mysql

[Jon Miller]

In my experience in programming databases many moons ago (I'm talking
DOS base systems of the early 80's) We were told to use Name fields to
Index on to help with searches and use a field that would hold a unique
data for the Primary field.  With that in mind I always found the
auto-increment field such as CUSTID as the best choice.  After all there
each customer should have a unique account number that is not
duplicated.

Jon
On Thu, 2003-01-02 at 05:57, Hook wrote:
> Arie Hol wrote:
> > Indexes are 'unique' fields in a table - and cannot in any way be
> duplicated
> > (otherwise point less having an index) - thus to increase the efficiency
> it
> > is often better to have an auto-increment as an index in a table.
> 
> Not so. A primary key is by definition unique, and an index can be defined
> as holding only unique values, but in general an index is just a short way
> of finding data, there's no need for uniqueness.  Most of the indexes into
> database tables that I've used/created aren't unique (except for
> auto_increment fields of course).
> 
> The Hooker
> 
-- 
Jon Miller <jlmiller at mmtnetworks.com.au>
MMT Networks Pty Ltd