Method of using cache to determine the visibility to a remote database client of a plurality of database transactions

• US 20030135523A1
• Filed: 07/25/2002
• Published: 07/17/2003
• Est. Priority Date: 02/26/1997
• Status: Active Grant

• Current Assignee: Peter S. Lim, Robert A. Brodersen
• Original Assignee: Peter S. Lim, Robert A. Brodersen
• Inventors: Lim, Peter S., Brodersen, Robert A.
• Granted Patent: US 6,684,438 B2
• Time in Patent Office: Days
• US Class Current: 707/201
• CPC Class Codes: G06F 16/278 Data partitioning, e.g. horizontal or vertical partitioning
• CPC Class Codes: Y10S 707/99936 Pattern matching access
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users

Abstract

Updates made to a central database (3) or to another partially replicated database (23-1) are selectively propagated to a partially replicated database (23-2) if the owner of the partially replicated database (23-2) is deemed to have visibility to the data being updated. Visibility is determined by use of predetermined rules stored in a rules database. Stored rules are assessed against data content of various tables that make up a logical entity, known as a docking object that is being updated. The stored rules are assessed against data content of various tables that make up a docking object, not necessarily being the docking object that is being updated. The visibility rules of these related docking objects are recursively determined. Changes in visibility are determined to enable the central computer to direct the nodes to insert the docking object into its partially replicated database. The predetermined rules are in a declarative form and specify visibility of data based upon structure of the data without reference to data content. Database objects and transactions have an associated visibility strength used to determine the visibility of a transaction to an object.

Claims

1. A method of managing a database, said database including a central database and separate partially replicated databases (23a, 23b, 23c), said separate partially replicated databases (23a, 23b, 23c) having separate users (33a, 33b, 33c), comprising determining the visibility of a user (33a, 33b, 33c) of a partially replicated database (23a, 23b, 23c) to data being propagated, storing in cache memory the visibility of the user (33a, 33b, 33c) of the partially replicated database (23a, 23b, 23c), and propagating said data to the partially replicated database (23a, 23b, 23c) only if the user (33a, 33b, 33c) of the partially replicated database (23a, 23b, 23c) has visibility to the data.

2. An article of manufacture comprising a computer usable medium having computer usable program code embodied therein for managing a partially replicated database (23a, 23b, 23c) by determining the visibility of a user (33a, 33b, 33c) of a partially replicated database (23a, 23b, 23c) to data being propagated, storing in cache memory the visibility of the user (33a, 33b, 33c) of the partially replicated database (23a, 23b, 23c), and propagating said data to a partially replicated database (23a, 23b, 23c) only if the user (33a, 33b, 33c) of the partially replicated database (23a, 23b, 23c) has visibility to the data, the computer readable program means in said article of manufacture comprising:

computer readable program code means for causing a computer to effect determining the visibility of a user (33a, 33b, 33c) of the partially replicated database (23a, 23b, 23c) to data being propagated; and

computer readable program code means for causing the computer to effect storing in cache memory the visibility of the user (33a, 33b, 33c) of the partially replicated database (23a, 23b, 23c);

and computer readable program code means for causing a computer to effect propagating said data to the partially replicated database (23a, 23b, 23c) only if the user (33a, 33b, 33c) of the partially replicated database (23a, 23b, 23c) has visibility to the data.

3. A program storage device readable by a machine, tangibly embodying a program of instructions executable by a machine to perform method steps for managing a database, said method steps comprising determining the visibility of a user (33a, 33b, 33c) of the partially replicated database (23a, 23b, 23c) to data being propagated, storing in cache memory the visibility of the user (33a, 33b, 33c) of the partially replicated database (23a, 23b, 23c), and propagating said data to the partially replicated database (23a, 23b, 23c) only if the user (33a, 33b, 33c) of the partially replicated database (23a, 23b, 23c) has visibility to the data.