Extensible rules engine in a database management system

• US 20030212657A1
• Filed: 04/17/2003
• Published: 11/13/2003
• Est. Priority Date: 05/10/2002
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Wang, Wei, Gawlick, Dieter, Stamos, James, Kaluskar, Sanjay
• Granted Patent: US 7,366,713 B2
• Time in Patent Office: Days
• US Class Current: 707/1
• CPC Class Codes: G06F 16/21 Design, administration or maintenance of databases
• CPC Class Codes: G06F 16/86 Mapping to a database
• CPC Class Codes: G06F 40/137 Hierarchical processing, e.g. outlines
• CPC Class Codes: Y10S 707/961 Associative
• CPC Class Codes: Y10S 707/99933 Query processing, i.e. searching
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

An extensible rules engine that uses database technology provides a rules evaluation service for applications external to the database server or database management system. Applications are able to utilize the rules engine to provide alternative behaviors based on information against which specified conditions are evaluated. A framework is provided for specifying data definitions that can be referenced by user-defined rules, through creation and use of an evaluation context. Application-specific data types can be defined by specifying data tables and/or variables that can be referenced by rules created for evaluation against data that is associated with the evaluation context. The data against which rules are evaluated can be provided as an in-memory object. A security model is provided in which the privilege to create rules according to a particular evaluation context is controlled by one privilege, whereas the privilege to access underlying tables or variables is controlled by another privilege.

Claims

1. A method for evaluating rules in a database system, the method comprising the steps of:

receiving an evaluation context that specifies what can be referenced in a corresponding rule condition;

receiving a set of one or more rules, wherein each rule includes a rule condition; and

evaluating one or more rules from the set of rules against information that is specified in the evaluation context to determine whether a rule condition is satisfied.

2. The method of claim 1, wherein the step of receiving an evaluation context includes receiving an evaluation context that specifies a list of one or more data tables that can be referenced in a corresponding rule condition.

3. The method of claim 1, wherein the step of receiving an evaluation context includes receiving an evaluation context that defines one or more variables that can be referenced in a corresponding rule condition.

4. The method of claim 1, wherein the step of receiving an evaluation context includes receiving an evaluation context that specifies a list of one or more data tables and defines one or more variables that can be referenced in a corresponding rule condition.

5. The method of claim 1,

wherein the step of receiving an evaluation context includes receiving an evaluation context that specifies a list of one or more data tables that can be referenced in a corresponding rule condition;

and the method further comprises the steps of;

controlling management of the evaluation context with a first security privilege; and

controlling access to the one or more tables with a second security privilege that is different than the first security privilege.

6. The method of claim 1,

wherein the steps of receiving include receiving from a software application;

wherein the step of evaluating is performed by a database server; and

wherein the software application is different than the database server.

7. The method of claim 6, further comprising the step of:

receiving, from the software application, the information against which the set of rules is evaluated.

8. The method of claim 1,

wherein the step of receiving a set of rules includes receiving a rule that includes a first rule condition and a second rule condition that is disjunctively related to the first rule condition and wherein the first rule condition includes a third rule condition and a fourth rule condition that is conjunctively related to the third rule condition;

wherein the information that the one or more rules are evaluated against includes third information that is associated with the third condition and does not include fourth information that is associated with the fourth condition; and

wherein the step of evaluating includes

evaluating the third condition against the third information to determine whether the third condition is satisfied by the third information;

if the third condition is not satisfied by the third information, then returning an indication that the first condition is not satisfied; and

if the third condition is satisfied by the third information, then returning an indication that the first condition may be satisfied.

9. The method of claim 8, wherein the third condition is a simple rule condition.

10. The method of claim 8, wherein:

if at least one indication is returned that the first condition is satisfied or that the second condition is satisfied, then returning an indication that the rule is satisfied;

if no indication is returned that the first condition is satisfied or that the second condition is satisfied and if at least one indication is returned that the first condition may be satisfied or that the second condition may be satisfied, then returning an indication that the rule may be satisfied; and

if no indication is returned that the first condition is satisfied or that the second condition is satisfied and no indication is returned that the first condition may be satisfied or that the second condition may be satisfied, then returning an indication that the rule is not satisfied.

11. The method of claim 1, wherein the step of receiving an evaluation context includes receiving an evaluation context that is associated with a subset of the set of rules.

12. The method of claim 1, wherein the step of receiving an evaluation context includes receiving an evaluation context that is associated with each rule of the set of rules.

13. The method of claim 1, wherein the step of receiving an evaluation context and the step of receiving the set of rules are performed by a single act of receiving a message that includes both the evaluation context and the set of rules.

14. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 1.

15. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 2.

16. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 3.

17. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 4.

18. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 5.

19. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 6.

20. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 7.

21. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 8.

22. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 9.

23. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 10.

24. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 11.

25. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 12.

26. A computer-readable medium carrying one or more sequences of instructions which, when executed by one or more processors, causes the one or more processors to perform the method recited in claim 13.

27. An apparatus for evaluating rules in a database system, the apparatus comprising:

means for receiving an evaluation context that specifies what can be referenced in a corresponding rule condition;

means for receiving a set of one or more rules, wherein each rule includes a rule condition; and

means for evaluating one or more rules from the set of rules against information that is specified in the evaluation context to determine whether a rule condition is satisfied.