Browse Prior Art Database

Managing Transition Information in a Set Oriented Database Production Rule System

IP.com Disclosure Number: IPCOM000121688D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 1 page(s) / 36K

Publishing Venue

IBM

Related People

Cochrane, RJ: AUTHOR [+3]

Abstract

Disclosed is a production rule system in the database environment which allows users to specify database operations that are performed automatically when certain events occur and/or conditions are met. A set-oriented rule system has been designed and implemented meaning that rules are triggered by, can refer to, and can perform arbitrary sets of changes to the database. These sets of changes are referred to as transitions and are accessed by rules through logical transition tables.

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Managing Transition Information in a Set Oriented Database Production
Rule System

      Disclosed is a production rule system in the database
environment which allows users to specify database operations that
are performed automatically when certain events occur and/or
conditions are met.  A set-oriented rule system has been designed and
implemented meaning that rules are triggered by, can refer to, and
can perform arbitrary sets of changes to the database.  These sets of
changes are referred to as transitions and are accessed by rules
through logical transition tables.

      The implementation of a set-oriented rule system must include a
component for managing transition information. The component must
save enough information during database processing so that the rule
processor can efficiently determine which rules are triggered and can
materialize references to transition tables.

      A special data structure has been developed, the Transition
Log, that supports efficient methods for managing transition
information.  The Transition Log is a "double hash table", where each
record represents a single database operation.  Based on the set of
currently defined rules, records in the Transition Log are created
during database processing.  At any given time, hashing on an
operation and table yields a list of relevant records in reverse
order of occurrence.  Hashing on a table and tuple yields a similar
list of relevant records.  The Transition Log lends it...