Partial data model exposure through client side caching

• US 7,574,423 B2
• Filed: 03/20/2003
• Issued: 08/11/2009
• Est. Priority Date: 03/20/2003
• Status: Expired due to Fees

• 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.
• Primary Examiner(s): Alam; Hosain T
• Assistant Examiner(s): HARPER, ELIYAH STONE
• Application Number:
  US10/392,642
• Publication Number:
  US 20040186840A1
• Time in Patent Office: 2,336 Days
• Field of Search: 707/4, 707/5, 707/100, 707/104.1, 707/200, 707/202, 707/204, 707/7, 707/6, 707/206, 707/3, 707/10, 707/2
• US Class Current: 1/1
• 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 computer-implemented method for using a system that includes a client device and a server device described by a plurality of system parameters in building queries against a database represented by a data abstraction model, the method comprising:

receiving, from a user interacting with the client device, a first request to display one or more logical fields of the data abstraction model, wherein the data abstraction model includes a plurality of logical field fields representative of physical fields of the database, wherein each logical field includes a logical field definition specifying at least a name and an access method for accessing physical data elements stored in physical fields of the database corresponding to a respective logical field, and wherein each logical field provides a query element available for inclusion in an abstract query;

selectively retrieving, in response to the request, a portion of the data abstraction model that includes the one or more logical fields, based on system parameters that limit accessibility to the data abstraction model by the client device;

storing the retrieved portion of the data abstraction model in a cache available on the client device;

displaying the one or more logical fields to the user;

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

determining if there is sufficient available space in the cache to store the one or more logical fields specified by the second request;

in response to determining there is insufficient available space in the cache to store the one or more logical fields specified by the second request, selectively removing portions of the data abstraction model from the cache to make sufficient available space for the retrieved portion of the data abstraction model; and

displaying the one or more logical fields specified by the second request.

2. The method of claim 1, wherein the retrieved portion of the data abstraction 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 abstraction 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 abstraction model comprises some, but not all, logical fields in the common category.

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

receiving a first request from a user to access a first node, of the hierarchical tree structure of nodes, wherein each node identifies a respective plurality of logical field fields representative of physical fields of a database, wherein each logical field includes a logical field definition specifying at least a name and an access method for accessing physical data elements stored in physical fields of the database corresponding to a respective logical field, and wherein each logical field provides a query element available for inclusion in an abstract query;

in response to the request, selectively retrieving a portion of the plurality of logical fields identified by at least the first node based on a storage capacity of a cache available on a client device;

storing the retrieved portion of logical fields in the cache; and

presenting, to the user, the one or more links to other nodes of the hierarchical tree structure of nodes, associated with the first node;

receiving a second request to access one of the nodes linked to by the first node;

determining if there is sufficient available space in the cache to store the logical fields identified by the node specified by the second request;

if not, selectively removing one or more of the logical fields stored in the cache to free available space sufficient to store the logical fields of the node specified by the second request; and

presenting, to the user, the one or more logical fields specified by the second request.

7. The method of claim 6, wherein the retrieved portion of the plurality of logical fields identified by at least the first node includes logical fields retrieved from one or more nodes subordinate to the first node.

8. The method of claim 7, wherein the retrieved portion of the plurality of logical fields identified by at least the first node includes logical fields retrieved from one or more nodes subordinate to children of the first node.

9. The method of claim 6, wherein the hierarchical tree structure of nodes is contained in an XML document.

10. The method of claim 6, wherein each node represents a field or category of fields in a database.

11. The method of claim 6, wherein selectively removing one or more portions of the tree structure comprises maintaining logical fields from nodes in the cache that form a path from a root node to the first node.

12. The method of claim 6, wherein selectively removing one or more portions of the tree structure comprises traversing the tree structure in an ordered manner and removing logical fields associated with one or more leaf nodes of the tree structure.

13. The method of claim 12, 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.