Re: Nearest Common Ancestor Report (XDb1's $1000 Challenge)

> How does this critter perform on a simple query which extracts just > the record for "John Smith"...

Comparisions haven't been made yet but it should fair well in some cases. For example the name "john smith" in essence has a reference to all things with that name even if it is a dog. In this case resolving to the named things doesn't require traversing persons or dogs.

Below is an example of finding things based on intersections expressed via simple "relational expressions". Suppose user had entered the following data:

color isa thing.
black isa color.
white isa color.

person isa thing.
john smith isa person.
john smith is black.

mary isa person.
mary is white.

bob isa person.
bob is black.
bob is white. (he is both black and white)

dog isa thing.
fido isa dog.
fido is white.

Following query finds all persons:
(person)

Following query finds a person named mary
(person) mary

Following query finds a person named john smith:
(person) "john smith"

Following query finds all persons who are black (john & bob):
(person) (black)

Following query finds all persons who are black and white (only bob):
(person) (black) (white)

Following query finds all things that are white (mary & bob & fido!):
(white)

Other examples are posted in recent posts in comp.database.object and at www.xdb1.com/Example/Ex005.asp Received on Mon May 24 2004 - 20:10:51 CDT