Re: Demo: Modelling Cost of Travel Paths Between Towns

Neo: [With TM/XDb2] user can ... update the age of any thing whose name is john and has an age, including that of things whose class is unknown at design-time (ie a person, dog, cat, pig, plane, etc in the future). Try coding that in RM.

Alan: It doesn't get a whole lot easier

Neo: So let's step thru it and fill in the details...

Alan: If you can't tell me what data you will want to see two hours from now, you will not be working here much longer...

Neo: In AI-type applications, one can't anticipate what data R2D2 will store even two hours from now. I asked you to create a db and query by 9AM that will allow R2D2 to store (w/o NULLs and redundancy) those unforeeable things he will see at 11A and still have your 9AM query work correctly. Now you seems to think the request is ridiculous. Your are right, it is difficult to implement in RM in a practical manner.

Here is how with TM/XDb2:

08:45 Sit back and relax as there is no schema to design.

      XDb2 will accept whatever data R2D2 will give it 
      and store it without NULLs or redundancy. New things
      need not conform to any predefined tables or schema.

09:00 Write query to find things named john with an age property 
      that will work until eternity no matter what kind of things 
      R2D2 stores in db. Here it is (for the third time):
      SELECT %.age & %.name=john;

11:00 R2D2 meets/stores a dog named john, 
      age 2 with additional properties.
      9AM query still works!

12:00 R2D2 visits a volcano named john, age 13 with properties 
      none similar to anything stored earlier.
      9AM query still works!

13:00 R2D2 light travels to the next galaxy and discovers XYZ,
      names it john, determines its age and other characteristics 
      (none similar to anything stored earlier)
      9AM query still works!

"Lather, rinse, repeat, Lather, rinse, repeat, Lather, rinse...." Received on Thu Nov 18 2004 - 05:02:28 CET