RE: Design Question - Thoughts Needed

Tracy,

>The 1000 comp deductible does not equate to the same premium for all
vehicles.
>We also have one coverage where 3 columns are necessary to capture the covg
>info. There is a deductible, limit and premium associated with it. So do
we
>stick another column in the coverage table to capture for only this
coverage?

The short answer to your question is, yes, you design the vehicle-coverage table to meet the requirements of your application. Remember, each database table is an entity unto itself, and should be able to stand alone with the information that it is supposed to hold. In your case, if you decide that the vehicle-coverage table will hold the premium for each type of coverage for each vehicle, you place whatever columns you need to support the capture of the premium (as long as you do not violate normalization). It seems to me that you would have one column in the table that would hold the premium amount for all coverage types (for ease of reporting). If you need additional columns to explain how you calculated that amount, just add'em.

Yes, design is an art, not a science. After awhile, you will develop your own standards for database design, and it will get easier.

hope this helps.

Tom Mercadante
Oracle Certified Professional

-----Original Message-----
Sent: Monday, June 25, 2001 5:23 PM
To: Multiple recipients of list ORACLE-L

I think I may have confused some, regarding my previous post. The coverage and
amount is specific to the vehicle. It is not a set amount. For example:

Method #1
Vehicle/Coverage Table
Seq Year Type Annual_Miles Comp_Ded Comp_Prem Towing_Ded Towing_Prem Pip_Ded Pip_Limit Pip_Prem 1 97 Jeep 1000 500 25.25 50 10 "NULL"

     "NULL"         "NULL"
2    99   Truck     7000      1000       20.50          "NULL"
"NULL"
     "NULL"         "NULL"         "NULL"
3              98   Car  5000      1000       15.00          0         30
250       100000         35

Method #2
Vehicle Table
Seq Year Type Annual_Miles
1 97 Jeep 1000
2 99 Truck 7000
3 98 Car 5000

Coverage Table

Seq  Covg_Id   Covg_Ded  Covg_Limit      Covg_Prem
1    A(Comp)   500       "NULL"          25.25
1    B(Towing) 50        "NULL"          10
2    A         1000      "NULL"          20.50
3    A         1000      "NULL"          15
3    B         0         "NULL"          30
3    C(Pip)         250       100000          35

The 1000 comp deductible does not equate to the same premium for all vehicles.
We also have one coverage where 3 columns are necessary to capture the covg info. There is a deductible, limit and premium associated with it. So do we
stick another column in the coverage table to capture for only this coverage?
The saga continues. Now I understand when they say modeling is an art and not
a science. I was much better in science. (Thus my struggles)

• Forwarded by Tracy Rahmlow on 06/25/2001 01:52 PM Please respond to ORACLE-L_at_fatcity.com Sent by: root_at_fatcity.com To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com> cc:

Tracy,

I would fight tooth and nail for a separate auto_coverage table that is a child to each parent auto record. (It actually represents a many-to-many relationship between the auto table and the available_coverage table which lists all coverages available).

When you argue about performance problems during reporting, it pales in comparison to performance problems if, say, the coverage name changes, or if you want to know "Who/how many people have just towing". In my example, you query the child table for the coverage code that = towing. In your example, you query all parent records.

This is the real reason why normalization is required in relational design. Break everything down into it's smallest parts so you can query and update just the atomic item you need.

just my 2 cents.

Tom Mercadante
Oracle Certified Professional

-----Original Message-----
Sent: Monday, June 25, 2001 1:16 PM
To: Multiple recipients of list ORACLE-L

We are looking to redesign our current system and a question popped up that I
am struggling with. (our business is auto insurance). Each vehicle on a policy may have 1 or many coverages. For example, comprehensive, collision,
towing, property damage ... A couple of things: 1- some coverages will not apply because they are state specific. 2 - some coverages will not be chosen
by the insured. Therefore, should I have a vehicle table with each coverage and its premium as separate specific columns or should I add a coverage table
which will contain the coverage and premium. Under the later example if I have
10 coverages and I want to print them on the insured's declaration page don't I
have a possible performance problem with up to 10 i/os. Where as with the first example I only have 1 read but possible space wastage. I know in 1st normal form you should remove repeating groups, in my case is a coverage a repeating group? Where do you draw the line? For example, clients may have
multiple phone numbers although I don't see many examples where the phone numbers are split into another table. Please share any thoughts that may make
my decision easier. Thanks

Just an fyi, in our current design the coverages have been stored with the vehicle.

--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Tracy Rahmlow
  INET: Tracy.Rahmlow_at_aexp.com

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Mercadante, Thomas F
  INET: NDATFM_at_labor.state.ny.us

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