PTAB

IPR2014-00575

Microsoft Corp v. Enfish LLC

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Petition
petition Intelligence

1. Case Identification

2. Patent Overview

  • Title: Self-Referential Database with Variable Length OIDs
  • Brief Description: The ’604 patent discloses a database system featuring a single, "self-referential" logical table that stores both data and schema information in the same structure. Key aspects include the use of variable-length object identification numbers (OIDs) to identify rows and columns, and a bi-directional indexing method for contextual searching.

3. Grounds for Unpatentability

Ground 1: Anticipation of Indexing Claims - Claims 17, 24-26, 47, and 54-56 are anticipated by Smith.

  • Prior Art Relied Upon: Smith (Patent 5,404,510).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Smith, which is directed to the design of indexes in a relational database management system, discloses every limitation of the challenged independent claims. Smith was asserted to teach a database system with logical tables comprising rows and columns, where rows are identified by OIDs (e.g., an "employee ID") and columns have their own OIDs (e.g., "column object id"). Furthermore, Smith explicitly teaches the core additional limitation of these claims: indexing data stored within the table to reduce the time required to locate records.
    • Key Aspects: This ground was presented to streamline the proceeding in light of the Patent Owner's evolving claim construction positions in a co-pending district court litigation. Petitioner argued that Smith's disclosure of explicit "object ids" anticipates the claims even under the Patent Owner's newly-proffered narrow construction of OIDs as "immutable," making the Smith reference non-redundant to previously asserted art.

Ground 2: Obviousness of Variable-Length OID Claims - Claims 16 and 46 are obvious over SQL-92 in view of Gardarin and Smith.

  • Prior Art Relied Upon: SQL-92 (ANSI Standard Query Language-92), Gardarin (ESQL2 - Extending SQL2 to Support Object-Oriented & Deductive Databases (1992)), and Smith (Patent 5,404,510).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that SQL-92, as the dominant database standard at the time, taught the base limitations of a logical table with rows and columns. To address the key additional limitation of "wherein said OIDs are variable length," Petitioner added Gardarin. Gardarin explicitly teaches using a variable-length data type ("Character Varying"), as defined within the SQL-92 framework, as a primary key for a table, thus disclosing variable-length row OIDs. Smith was included for its teachings on efficiently designing and managing indexes, a feature not standardized by SQL-92 but understood to be an ordinary and expected component of a complete database system.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the standard database structure of SQL-92 with Gardarin's explicit teachings on variable-length primary keys to implement that specific, known feature. A POSITA would further be motivated to incorporate Smith's well-known indexing optimization techniques into the SQL-compliant system, as the SQL-92 standard intentionally left indexing approaches open for such improvements by individual providers.
    • Expectation of Success: Combining these established database concepts—a structural standard (SQL-92), a specific feature implementation (Gardarin), and a common optimization technique (Smith)—was argued to be a predictable integration of known elements that would have yielded the claimed invention.

Ground 3: Obviousness of Advanced Search Claims - Claims 28-29 and 58-59 are obvious over Smith in view of Clifton and Salton.

  • Prior Art Relied Upon: Smith (Patent 5,404,510), Clifton (Indexing in a Hypertext Database), and Salton (Introduction to Modern Information Retrieval).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Smith provided the foundational relational database with indexing. Clifton was added to teach a secondary indexing system where an initial query result (a retrieved cell) itself points to another index, addressing the limitations of parent claims 27 and 57. To meet the specific limitations of claims 28-29 and 58-59, Petitioner introduced Salton, a well-known textbook. Salton supplied the necessary teachings for "weighing" keywords to rank results (claims 28/58) and "filtering" keywords by removing common "stop words" (claims 29/59), thereby improving search relevance.
    • Motivation to Combine: A POSITA improving upon Smith's database would look to analogous art like Clifton to implement more complex, multi-level indexing. To solve the well-known problem of full-text search relevance in such a system, the POSITA would be motivated to consult a standard reference like Salton to implement established techniques like term weighting and stop-word filtering.
    • Expectation of Success: Implementing Salton's well-documented and standard search optimization techniques into the database systems of Smith and Clifton would have been a straightforward application of known principles to achieve the predictable result of improved search quality.
  • Additional Grounds: Petitioner asserted that claims 18 and 48 are obvious over Smith in view of VB3, arguing VB3 teaches how to encapsulate Smith's database concepts within programming objects. Petitioner also argued claims 27 and 57 are obvious over Smith in view of Clifton, with Clifton teaching a secondary indexing structure where a retrieved object points to another index.

4. Key Claim Construction Positions

  • Object Identification Number (OID): Petitioner highlighted a critical dispute over the meaning of "OID." Petitioner noted that while the Board and Petitioner had previously favored a broad construction (e.g., "a value that identifies an object"), the Patent Owner had recently argued in parallel litigation for a much narrower construction where OIDs must be "immutable and completely independent of changes in data value or physical location." Petitioner presented its grounds, particularly its reliance on the Smith patent, to demonstrate the unpatentability of the challenged claims even under this new, narrower construction proposed by the Patent Owner.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 16-18, 24-29, 46-48, and 54-59 of the '604 patent as unpatentable.