Partial data model exposure through client side caching

• US 20040186840A1
• Filed: 03/20/2003
• Published: 09/23/2004
• Est. Priority Date: 03/20/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Dettinger, Richard D., Stevens, Richard J., Will, Eric W., Kulack, Frederick A.
• Granted Patent: US 7,574,423 B2
• Time in Patent Office: Days
• US Class Current: 707/100
• CPC Class Codes: G06F 16/2423 Interactive query statement specification based on a database schema
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99935 Query augmenting and refining, e.g. inexact access

Abstract

The present invention generally provides methods, articles of manufacture and systems for exposing, on a client device, fields of a data model representing an underlying database for use in building queries against the database. For some embodiments, the client device may be a device having limited resources, such as a handheld computing device. Therefore, rather than load and expose the entire data model on the client at once, a limited portion of the data model may be exposed on a client in a “just in time” (JIT) basis. The limited portion may be determined, for example, based on input received from a user and system parameters, such as the system memory and network bandwidth available to the client device.

Claims

1. A method for use in building queries against a database represented by a data model comprising logical fields representative of physical fields of the database, the method comprising:

receiving, from a user, a request to display one or more logical fields of the data model;

retrieving, in response to the request, a portion of the data model related to the one or more logical fields;

storing the retrieved portion of the data model in a cache; and

displaying the one or more logical fields to the user.

2. The method of claim 1, wherein the retrieved portion of the data model comprises at least one of the one or more logical fields the user requested to display.

3. The method of claim 1, wherein the one or more logical fields are displayed to the user prior to retrieving the portion of the data model.

4. The method of claim 1, wherein:

at least some of the logical fields are organized as categories; and

receiving the request from the user comprises receiving a request to display one or more logical fields in a common category.

5. The method of claim 4, wherein the retrieved portion of the data model comprises some, but not all, logical fields in the common category.

6. The method of claim 1, further comprising:

determining if there is sufficient available space in the cache to hold the retrieved portion of the data model; and

in response to determining there is not sufficient available space in the cache to hold the requested entities, selectively removing portions of the data model from the cache to make sufficient available space for the retrieved portion of the data model.

7. A method for accessing a hierarchical tree structure of nodes, the method comprising:

receiving a request from a user to access one or more entities associated with a first node;

in response to the request, retrieving a portion of the tree structure related to the first node;

storing the retrieved portion of the tree structure in a cache; and

presenting, to the user, the one or more entities associated with the first node.

8. The method of claim 7, wherein the retrieved portion of the tree structure comprises one or more nodes subordinate to the first node.

9. The method of claim 8, wherein the retrieved portion of the tree structure comprises one or more nodes subordinate to children of the first node.

10. The method of claim 7, wherein the hierarchical tree structure of nodes is contained in an XML document.

11. The method of claim 7, wherein each node represents a field or category of fields in a database.

12. The method of claim 7, further comprising, prior to storing the retrieved portion of the tree structure:

determining if there is sufficient available space in the cache to store the retrieved portion of the tree structure; and

if not, selectively removing one or more portions of the tree structure stored in the cache to free available space sufficient to store the retrieved portion of the tree structure.

13. The method of claim 12, wherein selectively removing one or more portions of the tree structure comprises maintaining nodes in the cache that form a path from a root node to the first node.

14. The method of claim 12, wherein selectively removing one or more portions of the tree structure comprises traversing the tree structure in an ordered manner and removing leaf nodes.

15. The method of claim 14, wherein traversing the tree structure in an ordered manner comprises iteratively:

moving up a level from the first node to select a node in a direct ancestral path between a root node and the first node; and

removing at least one of a sibling node of the selected node or a subordinate node to a sibling node of the selected node.

16. A computer readable medium containing a program which, when executed by a processor, performs operations for building queries against a database represented by a data model, the operations comprising:

providing an interface for building a query against the database;

receiving, via the interface, a request from to display one or more entities of the data model;

retrieving, in response to the request, a portion of the data model related to the one or more entities;

storing the retrieved portion of the data model in a cache; and

displaying the one or more entities on the interface.

17. The computer readable medium of claim 16, wherein the one or more entities comprise at least one of a field or category of fields of the database.

18. The computer readable medium of claim 16, wherein receiving the request comprises receiving a request to display one or more fields of the database organized in a common category.

19. The computer readable medium of claim 16, wherein the one or more entities are displayed prior to retrieving the portion of the data model.

20. A data processing system, comprising:

a database;

a data abstraction model comprising logical fields representative of physical fields of the database; and

a client device comprising a cache and an executable component configured to,

maintain a limited portion of the data abstraction model in the cache, the limited portion comprising one or more logical fields determined by input received via a graphical user interface, and

expose, via the graphical user interface, one or more of the logical fields maintained in the cache.

21. The data processing system of claim 20, wherein the client device is a handheld computing device.

22. The data processing system of claim 21, wherein the executable component is configured to retrieve a portion of the data model via a wireless connection between the client device and a network.

23. The data processing system of claim 20, wherein the executable component is configured to maintain a limited portion of the data abstraction model in the cache by:

receiving, via the graphical user interface, a selected category of logical fields;

retrieving, in response to the request, a portion of the data abstraction model related to the selected category of logical fields; and

storing the retrieved portion of the data abstraction model in the cache.

24. The data processing system of claim 23, wherein the retrieved portion of the data abstraction model comprises at least some logical fields of the selected category.

25. The data processing system of claim 23, wherein at least some logical fields of the selected category are maintained in the cache prior to selection of the category.

26. The data processing system of claim 23, wherein the client application is configured to maintain a limited portion of the data abstraction model in the cache by selectively removing portions of the data abstraction model from the cache prior to storing the retrieved portion of the data abstraction model in the cache.