"Dual criteria indexes" (was Re: What should fp 6.0 look like?)

[Kenneth Brody]

Howie wrote:
[...]
> | > associated fields working in dual criteria index's
> |
> | What is a "dual criteria index", and what "doesn't work" with them with
> | associated fields?
> |
> 
> It hasn't worked in quite a while.
> 
> I assumed you and fptech were aware of it.

Perhaps so, but not with the term "dual criteria index".

> Example: You have a records with a set of state fields where {S1) PU State"
> are up to 10 states that the company picks up from and "S2) Delv State" are
> 10 states the company delivers to.
> 
> If you build an index on s1) as the first criteria and s2) as the second and
> try to use it to find a company that picks up in say NJ and delivers to CA
> nothing will be returned, even though many records contain the requested
> data.
> 
> I understand that the example seems flawed and it should return any record
> that contains NJ in any of the S1) fields and CA in any of the S2) fields
> but that's exactly what we want - only nothing is returned.

It's working exactly as designed, and it's doing exactly what you told
it to do.  (Though not what you meant to tell it to do.)

You have group S1 as the pick-up states, and S2 as the delivery states.
Since they are both S groups, you have told filePro that they are
matched pairs.

For example:

    @AF     1    2    3    4
    S1      NY   NJ   DC   FL
    S2      CA   WA   OR   TX

This means that they pick up in New York and deliver to California, pick up
in New Jersey and deliver in Washington, pick up in DC and deliver in Oregon,
and pick up in Florida and deliver in Texas.

If you build and index on S1 and S2, and look for a pickup of NJ and a
delivery of CA, you won't find one here.  (ie: the NJ pickup gets delivered
to WA, and the delivery to CA was picked up in NY.)

Based on your description (a list of pickups, and an unrelated list of
deliveries), you need to use separate groups (such as S1 and T1).


-- 
+-------------------------+--------------------+-----------------------------+
| Kenneth J. Brody        | www.hvcomputer.com |                             |
| kenbrody/at\spamcop.net | www.fptech.com     | #include <std_disclaimer.h> |
+-------------------------+--------------------+-----------------------------+
Don't e-mail me at: <ThisIsASpamTrap at gmail.com>