Patent ID: 7412452

Claim:
A data storage and retrieval system stored on a computer readable memory in a computer system having at least one processor, comprising: a plurality of information items, each of said information items including at least one property; a plurality of intensional category definitions operable to provide dynamic categorization of said plurality of information items, wherein each of said intensional information item category definitions includes a predicate, wherein said predicate is operable to identify an input one of said information items as a member of a category based on said at least one property in said input one of said information items, wherein said category definitions are stored separately from said information items, and wherein said category definitions maintain no references to any one of said information items; an information item and category interface operable to receive a new information item and dynamically add said information item to said plurality of information items, wherein said new information item is dynamically created independently from creating or modifying any of said plurality of intensional category definitions, receive a new intensional category definition and dynamically add said new intensional category definition to said plurality of intensional category definitions, wherein said new intensional category definition is created independent from and without creating or modifying any of said plurality of information items, and receive a modification to an existing one of said plurality of information items and dynamically modify said one of said plurality of information items, wherein said modification is performed independent from and without creating or modifying any of said plurality of intensional category definitions; categorization logic operable to categorize said plurality of information items using said intensional category definitions, including said new intensional category definition, to populate at least one pre-computed category membership data structure to support efficient processing of at least one query, independent from creating or modifying any of said plurality of information items, wherein said categorization of said plurality of information items using said intensional category definitions including said new intensional category definition results in at least one of said plurality of information items existing prior to creation of said new intentional category definition participating in a category defined by said new intensional category definition; and an information item retrieval graphical user interface operable to receive said at least one input query from a user, wherein said input query indicates a subset of said plurality of information items by identification of at least one of said intensional category definitions.