Microsoft Corp v. Enfish LLC

1. Case Identification

• Case #: IPR2013-00559
• Patent #: 6,163,775
• Filed: September 3, 2013
• Petitioner(s): Microsoft Corporation
• Patent Owner(s): Enfish, LLC
• Challenged Claims: 1-15 and 31-45

2. Patent Overview

• Title: Self-Referential Database System
• Brief Description: The ’775 patent relates to a user-adjustable database system using a single, flexible, "self-referential" logical table. The system stores both data and schema information in the same table, where certain rows define the columns, and utilizes variable-length Object Identification Numbers (OIDs) for data elements.

3. Grounds for Unpatentability

Ground 1: Anticipation of Core Claims - Claims 1, 2, 31, 32, and 41 are anticipated by Chang under 35 U.S.C. §102(b).

• Prior Art Relied Upon: Chang (European Patent Application No. 0336580A2).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Chang, which teaches consolidating database table definition information into system catalog tables (e.g., SYS.COLUMNS), discloses every limitation of the independent claims. Chang's system tables were asserted to be "logical tables" where rows (records) and columns (attribute sets) are identified by values like record IDs and column numbers, which function as the claimed OIDs. The petition contended that Chang’s SYS.COLUMNS table, which defines all columns in the database including its own, is inherently self-referential. Specifically, a row in this table that defines a column constitutes a record whose OID (e.g., a record ID) is equal to the OID of the corresponding attribute set (the column itself) it defines, thus anticipating the patent’s core inventive concept.

Ground 2: Obviousness over Chang and Smith ’510 - Claims 1, 2, 31, 32, and 41 are obvious over Chang in view of Smith ’510.

• Prior Art Relied Upon: Chang (European Patent Application No. 0336580A2) and Smith ’510 (Patent 5,404,510).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that to the extent Chang is found not to adequately teach the use of OIDs for both records/rows and attribute sets/columns, Smith ’510 explicitly discloses and uses both concepts. Smith ’510 describes a database system with tables where each record has an "employee ID number" (functioning as a row OID) and columns have "column object id's."
  • Motivation to Combine: A POSITA would combine the teachings because both references are directed to improving the efficiency of relational database systems. Given that Chang seeks to speed input/output operations by consolidating a record’s defining information, incorporating the explicit row and column OID structures from Smith ’510 would be a logical and beneficial step to further enhance data retrieval and management.
  • Expectation of Success: Combining known OID structures from one relational database system (Smith ’510) with the table structure of another (Chang) would have been a predictable and straightforward implementation for a database designer.

Ground 3: Obviousness of Pointer Functionality over Chang and Horn - Claim 11 is obvious over Chang in view of Horn.

• Prior Art Relied Upon: Chang (European Patent Application No. 0336580A2) and Horn (Patent 5,226,158).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner asserted that while Chang provides the foundational self-referential table, it arguably does not explicitly disclose a key feature of claim 11: a cell containing a pointer to a different record. Horn was argued to supply this teaching by disclosing the use of row-to-row pointers to show relationships between records in the same table, such as linking an employee's record to their manager's record.
  • Motivation to Combine: A POSITA would combine the references to implement well-known relational database functionality into Chang's architecture. Adding the ability to link related records (e.g., employees to managers) is a common requirement in database design. Since both patents address the efficient design of relational databases, combining them to create a more functional system would have been an obvious design choice.
  • Expectation of Success: Implementing a standard record-pointer feature as taught by Horn into the table structure of Chang was presented as a routine task with a high expectation of success.

• Additional Grounds: Petitioner asserted numerous additional obviousness grounds against various claims. These grounds relied on the primary Chang reference combined with other prior art to teach specific functionalities, including: Webb for record-to-record pointers and type definitions; Smith ’162 for folder-type records and search paths; Dickerson and Crus for reciprocal synchronization and pointers between attribute sets; and Goldberg, Anderson, Jenness, and Covey for other specific database features.

4. Key Claim Construction Positions

• Logical Table: Petitioner proposed construing this term as "a conceptual framework that organizes data into rows and columns." This construction was argued to be consistent with the specification's distinction between a logical structure and a physical implementation in memory, emphasizing the abstract data model rather than how it is stored.
• Object Identification Number / OID: Petitioner proposed this term be construed as "a value that identifies an object." This broad construction was advanced to encompass various identifiers disclosed in the prior art, such as simple numbers (e.g., column or row numbers), textual names, or composite values, arguing that the patent does not limit OIDs to direct memory pointers.

5. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-15 and 31-45 of the ’775 patent as unpatentable.