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

[tom heine]

i tried it and it didn't work for me.  same results




> 
> 
> | 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).
> |
> 
> Wow! I am so glad to be wrong about this one - It solves a number of
> problems that we have been having.
> 
> I tested it and it works as Ken says, at least in DOS - I will test UNIX
> later.
> 
> filePro and Ken are even smarter than I give them credit for.
> 
> Howie
> 
> 
> 
>