Inheritance vs Alternative Pruning and Imputed Defaults

From: James Bowery (jim_bowery_at_hotmail.com)
Date: 09/05/04

  • Next message: Tom Breton: "Re: Inheritance vs Alternative Pruning and Imputed Defaults" 
    Date: 4 Sep 2004 16:35:51 -0700

    Almost all the Object Oriented stuff people layer on predicates are,
    at best, an ad hoc, and poor, means of optimizing execution speed.

    Let me explain.

    One of the principles of polymorphism is that the same method has the
    same abstract meaning regardless of the kind of object. A predicate
    considered as a method subsumes such polymorphism by simply trying the
    various possible implementations of the method and committing to only
    those that succeed. If more than one succeeds then so be it -- that's
    the whole idea of relations as opposed to functions.

    So, one reason you want all this OO stuff is the inheritance
    hierarchies keep you from going through all possible interpretations
    of
    a given method when the vast majority of them will fail for a given
    object.

    Another, related, problem is that inheritance provides defaults
    without requiring a lot of thinking on the part of the computer. What
    I mean by "thinking" here is the sort of thing that is done by
    statistical imputation of missing data via algorithms like expectation
    maximization (EM) or multi-relational data mining via inductive logic
    programming.

    So, the other reason you want all this OO stuff is so you can avoid
    mining a background database to provide reasonable defaults for
    various aspects of the data.

    However, and this is the important point, the work that has been
    expended toward OO facilities has vastly outstripped the effort that
    which has been put toward more parsimonious ways of optimizing
    predicate systems.

    Isn't there a school of thought that is more purist/parsimonious about
    the way predicates should be used to address the concerns of the OO
    community?

  • Next message: Tom Breton: "Re: Inheritance vs Alternative Pruning and Imputed Defaults"

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