Prefetching and caching persistent objects

• US 6,728,726 B1
• Filed: 03/05/1999
• Issued: 04/27/2004
• Est. Priority Date: 03/05/1999
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Pal, Shankar, Bernstein, Philip A., Shutt, David R.
• Primary Examiner(s): Alam, Shahid
• Assistant Examiner(s): FLEURANTIN, JEAN B
• Application Number:
  US09/263,408
• Time in Patent Office: 1,880 Days
• Field of Search: 707/3-5, 707/100-104, 707/204, 711/204, 709/229, 709/129
• US Class Current: 1/1
• CPC Class Codes: G06F 16/289 Object oriented databases
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

Prefetching and caching persistent objects is disclosed. The system creates a structure context used to identify a set containing a first object and other related objects. The objects have attributes, where each attribute is identified by a name. Upon a fetch of an attribute in the first object, the system also fetches related data. The related data includes other attributes in the object, and attributes in the other objects of the set having the same name as the attribute fetched for the first object.

Claims

1. A computerized method for retrieving data for an object or related objects prior to an explicit request for access to the data by a computing application comprising the steps of:

creating a structure context description identifying a structure context that comprises a set containing objects, wherein the objects have at least one attribute,

wherein the structure context description is stored in a relationship table having a plurality of rows containing items that describe the structure context,

wherein the structure context description contains enough information to retrieve all of the rows in the relationship table that describe all of the items in the structure context;

associating the structure context description with each object in the set, wherein the associating step associates the structure context description to each object in the set by creating a unique identifier between the structure context description and each object; and

fetching related object data for objects in the set by a data storage system from a physical storage system upon an access to an attribute of one object in the set, wherein the fetching step comprises

first retrieving object data requested by the computing application using the attribute,

returning the first requested object data to the requesting computing application,

retrieving related object data to the first requested object data using the attribute, and

placing in cache the related object data for future use by the application.

2. The computerized method as recited in claim 1, further comprising storing the structure context description, wherein the storing step comprises storing said structure context description in any of memory of a client application program, memory allocated to a data storage system, and table of a relational database, wherein said relational database is used as the physical storage system underlying a general data storage system.

3. The computerized method as recited in claim 1, wherein the data storage system is an object repository.

4. The computerized method as recited in claim 3, wherein the object repository implements an application programming interface (API) of Microsoft Repository.

5. The computerized method as recited in claim 4, wherein fetching related object data for the set and accessing an attribute of the first object occur asynchronously.

6. A computerized system comprising:

a computer comprising a processor, a memory, and a computer-readable medium operatively coupled together;

an operating environment executing in the processor from the computer readable medium;

a persistent storage system operative to store objects having attributes, structures, and structure contexts; and

a data storage system executing in the processor from the computer-readable medium and under the control of the operating environment, said data storage system operative to maintain objects in the persistent data storage system and further operative to retrieve data for an object or related objects prior to an explicit request for access to the data by a computing application,

such that a first object for a requested data item is first retrieved and passed back to the computing application and remaining related objects to the requested data item are then retrieved and placed in a cache by the data storage system for future use by the requesting computing application.

7. A computer-readable medium having computer readable instructions to cause a computer to perform a method comprising:

creating a structure context description identifying a set containing at least one object, the object having an attribute, said attribute having a name,

wherein the structure context description is stored in a relationship table having a plurality of rows containing items that describe the structure context,

wherein the structure context description contains enough information to retrieve all of the rows in the relationship table that describe all of the items in the structure context;

associating the structure context description with each data item in the object, wherein the associating step associates the structure context description to each object in the set by creating a unique identifier between the structure context description and each object; and

fetching related object data for the object in the set by a data storage system from a physical storage system upon an access to an attribute of the object in the set, wherein the fetching step comprises

first retrieving object data requested by the computing application using the attribute,

returning the first requested object data to the requesting computing application,

retrieving related object data to the first requested object data using the attribute, and

placing in cache the related object data for future use by the application.

8. A computerize method for retrieving data for an object or related objects prior to an explicit request for access to the data by a computing application comprising the steps of:

creating a structure context description identifying a structure context that comprises a set containing objects, wherein the objects have at least one attribute, and wherein the structure context description contains enough information to retrieve related objects from the object set;

associating the structure context description with each object in the set, wherein the associating step associates the structure context description to each object in the set by creating a unique identifier between the structure context description and each object;

fetching related object data for objects in the set by a data storage system from a physical storage system upon an access to an attribute of one object in the set, wherein the fetching step comprises

first retrieving object data requested by the computing application using the attribute,

returning the first requested object data to the requesting computing application,

retrieving related object data to the first requested object data using the attribute, and

placing in cache the related object data for future use by the application; and

deleting the structure context after a predetermined length of time, wherein the predetermined length of time occurs when there are no objects in the object set that reference the structure context remembered by the structure context description.