Microsoft Corp v. Enfish LLC

1. Case Identification

• Case #: IPR2013-00561
• Patent #: 6,163,775
• Filed: September 3, 2013
• Petitioner(s): Microsoft Corporation
• Patent Owner(s): Enfish, LLC
• Challenged Claims: 16, 24-30, 46, 54-60

2. Patent Overview

• Title: Self-Referential Database System
• Brief Description: The ’775 patent discloses a database system featuring a flexible, self-referential logical table that stores both data and schema information in a single table structure. The invention purports to improve on conventional databases by allowing columns to be defined by rows and using variable-length object identification numbers (OIDs) to identify rows and columns.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 24 and 54 under 35 U.S.C. §102(b) by VB3

• Prior Art Relied Upon: Visual Basic Programming System Manual for Windows Version 3.0 ("VB3"), a user manual published in 1993.
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that VB3, a well-known programming system predating the patent, disclosed every element of claims 24 and 54. VB3’s database management system taught using logical tables (e.g., Table, Dynaset, and Snapshot objects) that organize data into rows (records) and columns (fields/attribute sets). Petitioner asserted that cells in VB3 are identified by a combination of a record identifier (a first address segment) and a column identifier (a second address segment). VB3 also disclosed OIDs for records (primary keys or bookmark pointers) and for attribute sets (field ordinal positions or field pointers). Finally, VB3 explicitly taught creating indexes on tables, with cells in the index collection record pointing to an index object, thereby anticipating the limitations requiring a "pointer to an index record" and a "means for indexing."
  • Key Aspects: The argument relied on mapping VB3's conventional database terminology to the patent's claim language, asserting that the claimed features were standard components of database systems like the one described in VB3.

Ground 2: Anticipation of Claims 16 and 46 under 35 U.S.C. §102(b) by SQL-92

• Prior Art Relied Upon: The American National Standards Institute (ANSI) standard for Structured Query Language, SQL-92, published in 1992.
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that the widely adopted SQL-92 standard inherently disclosed the features of claims 16 and 46. SQL-92 defines logical tables with rows and columns, where each cell is identified by its row and column. Petitioner mapped the OID requirement for attribute sets to SQL-92’s column names or ordinal positions, and the OID requirement for records to primary keys or row numbers. The central limitation of these claims, "wherein said OIDs are variable length," was met because SQL-92 defines column names as variable-length character values (SQL_IDENTIFIER type) and permits primary keys to be defined using variable-length data types. Thus, Petitioner argued SQL-92 taught a complete database structure with variable-length OIDs as claimed.
  • Key Aspects: This ground asserted that the patent claims merely described fundamental and standardized features of relational databases that were ubiquitous years before the patent's priority date.

Ground 3: Obviousness of Claims 25-26 and 55-56 under 35 U.S.C. §103 over VB3 in view of Salton

• Prior Art Relied Upon: VB3 and Introduction to Modern Information Retrieval by Gerald Salton ("Salton").

• Core Argument for this Ground:

  • Prior Art Mapping: These claims depend from the claims challenged in Ground 1 and add limitations related to searching for keywords and creating index records. Petitioner argued that while VB3 provided the foundational database system with basic indexing, Salton provided explicit teachings on advanced text analysis and the creation of inverted indexes for efficient keyword searching. Salton described creating index structures that include every unique keyword from a document collection, with pointers from the keyword to the documents containing it. This directly taught the claimed "means for creating an index record for said key word."
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would have been motivated to combine the well-known indexing and text analysis techniques from a foundational text like Salton with a database system like VB3. The goal would be to improve the speed and efficiency of data retrieval, a common and predictable objective in database design.
  • Expectation of Success: A POSITA would have had a high expectation of success, as combining indexing algorithms with database systems was a standard and well-understood practice to enhance search performance.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including: (1) Claims 16 and 46 as obvious over SQL-92 in view of Chawathe (adding explicit variable-length OIDs); (2) Claims 27 and 57 as obvious over VB3 and Salton in view of Clifton (adding back-pointers from a cell to its index record); (3) Claims 28-30 and 58-60 as obvious over VB3 in view of Salton (adding weighing and filtering of search results); and (4) Claims 27 and 57 as obvious over VB3 in view of Smith ’510, Jensen, and Smith ’162 (providing an alternative combination for bi-directional pointers).

4. Key Claim Construction Positions

• "logical table": Petitioner proposed the construction "a conceptual framework that organizes data into rows and columns." This broad interpretation, based on extrinsic evidence like database textbooks, was crucial for mapping prior art structures like VB3's Table objects and SQL-92's standard tables, which organize data logically but may be stored differently physically, to the claims.
• "Object Identification Number (OID)": Petitioner proposed the construction "a value that identifies an object." This construction was intentionally broad to encompass various identifiers disclosed in the prior art, such as primary keys, pointers, ordinal positions, and textual names. Petitioner noted this broad view was consistent with Patent Owner's positions in co-pending district court litigation, thereby allowing prior art features like column names and row numbers to meet the OID limitations.

5. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 16, 24-30, 46, and 54-60 of the ’775 patent as unpatentable.