In-line triggers

• US 5,926,819 A
• Filed: 05/30/1997
• Issued: 07/20/1999
• Est. Priority Date: 05/30/1997
• Status: Expired due to Term

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle Corporation
• Inventors: Jain, Sandeep, Ramacher, Mark, Doo, Lip Boon
• Primary Examiner(s): Lintz, Paul R.
• Application Number:
  US08/866,823
• Time in Patent Office: 781 Days
• Field of Search: 707/2, 707/100, 707/102, 707/103, 707/104
• US Class Current: 1/1
• CPC Class Codes: G06F 16/24565 Triggers; Constraints
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99948 Application of database or data structure, e.g. distributed, multimedia, or image

Abstract

An in-line trigger is a modular, compiled, template trigger, which defines a series of actions to be performed when an operation is applied to a body of data. The series of actions to be performed when an in-line trigger fires are compiled into machine language instructions that receive three kinds of parameters: trigger-type specific parameters, operational metadata, and operational data. Trigger-type specific parameters are loaded into a section of run-time memory once for multiple firings of the same trigger. Operational metadata and operational data are loaded each time the trigger fires.

Claims

1. A method for applying an operation to a body of data, said method comprising the computer-implemented steps of:

determining whether there is a section of run-time memory associated with said operation, wherein said section of run-time memory comprises a compiled form of said operation and trigger-type specific parameters loaded from trigger-type specific data specified by a trigger defined for firing when said operation is applied to said body of data to cause a series of actions to be performed;

if there is not a section of run-time memory associated with said operation, then performing the steps of;

compiling said operation into said compiled form, and

loading said trigger-type specific data as said trigger-type specific parameters;

loading operational metadata that describes said body of data;

applying said operation to said body of data;

loading operational data that describes the effect of applying said operation;

causing said series of actions to be performed based on said trigger-type specific parameters, said operational metadata and said operational data.

2. The method of claim 1, wherein the step of causing a series of actions to be performed includes the step of causing said operation to be asynchronously replicated at a copy of said body of data.

3. The method of claim 1, wherein the step of causing a series of actions to be performed includes the step of causing said operation to be synchronously replicated at a second copy of said body of data.

4. The method of claim 1, wherein the step of causing a series of actions to be performed includes the step of causing said operation to be asynchronously replicated at a first copy of said body of data and synchronously replicated at a second copy of said body of data.

5. The method of claim 1, wherein the step of causing a series of actions to be performed includes the step of causing said operation to be reflected in a summary table.

6. The method of claim 1, further comprising the step of defining the trigger for firing when said operation is applied to the said of data, wherein the trigger specifies the series of actions and the trigger-type specific data.

7. The method of claim 6, wherein the step of defining the trigger for firing when said operation is applied to said body of data includes the step of defining the trigger for firing when a DML statement is applied to a row of a table.

8. The method of claim 6, wherein the step of defining the trigger for firing when said operation is applied to said body of data includes the steps of:

receiving said trigger-type specific data as input from a user; and

storing said trigger-type specific data as metadata associated with said trigger.

9. The method of claim 6, wherein:

the step of defining the trigger includes the step of storing a first reference to first instructions for causing said series of actions to be performed; and

the step of causing said series of actions to be performed based on said trigger-type specific parameters, said operational metadata, and said operational data includes the step of executing said first instructions based on said first reference with said trigger-type specific parameters, said operational metadata, and said operational data passed as parameters.

10. The method of claim 9, wherein:

the step of defining a trigger for firing when said operation is applied to said body of data includes the step of

storing a second reference to second instructions for loading trigger-type specific data into run-time memory; and

the step of loading trigger-type specific data as said trigger-type specific parameters includes the step of executing said second instructions based on said second reference.

11. The method of claim 9, wherein

the step of storing a first reference to first instructions includes the step of statically linking said first instructions to a database kernel.

12. The method of claim 9, wherein

the step of storing a first reference to first instructions includes the step of dynamically linking said first instructions to a database kernel.

13. The method of claim 9, wherein

the step of storing a first reference to first instructions includes the step of storing the name of a first executable file comprising said first instructions.

27. The computer readable medium of claim 9, wherein

the step of storing a first reference to first instructions includes the step of storing the name of a first executable file comprising said first instructions.

14. A computer system, comprising:

one or more modular compiled triggers;

a memory for storing trigger flags associated with a body of data for enabling one or more respective triggers from among the one or more modular compiled triggers; and

a database kernel configured to conditionally invoke, based on the trigger flags, said one or more respective triggers in response to a database event for the body of data.

15. The computer system of claim 14, wherein said database kernel is configured to invoke said one or more modular compiled triggers in response to receiving a request to perform a data manipulation language (DML) operation on the body of data.

16. The computer system of claim 15, further comprising:

a section of run-time memory for storing trigger-type specific parameters; and

means for passing said trigger-type specific parameters to a modular compiled trigger associated with said DML operation when invoking said modular compiled trigger.

17. The computer system of claim 16, wherein said one or more modular compiled triggers include a plurality of modular compiled replication triggers, wherein the modular compiled replication triggers, when invoked, cause a change made to a first copy of the body of data to be propagated to a second copy of the body of data.

18. A computer readable medium having stored thereon sequences of instructions for applying an operation to a body of data, said sequences of instructions including sequences of instructions for performing the steps of:

determining whether there is a section of run-time memory associated with said operation, wherein said section of run-time memory comprises a compiled form of said operation and trigger-type specific parameters loaded from trigger-type specific data specified by a trigger defined for firing when said operation is applied to said body of data to cause a series of actions to be performed;

if there is not a section of run-time memory associated with said operation, then performing the steps of;

compiling said operation into said compiled form, and

loading said trigger-type specific data as said trigger-type specific parameters;

loading operational metadata that describes said body of data;

applying said operation to said body of data;

loading operational data that describes the effect of applying said operation;

causing said series of actions to be performed based on said trigger-type specific parameters, said operational metadata and said operational data.

19. The computer readable medium of claim 18, wherein causing a series of actions to be performed includes the step of causing said operation to be asynchronously replicated at a copy of said body of data.

20. The computer readable medium of claim 18, wherein the step of causing a series of actions to be performed includes the step of causing said operation to be synchronously replicated at a second copy of said body of data.

21. The computer readable medium of claim 18, wherein the step of causing a series of actions to be performed includes the step of causing said operation to be asynchronously replicated at a first copy of said body of data and synchronously replicated at a second copy of said body of data.

22. The computer readable medium of claim 21, wherein the step of causing a series of actions to be performed includes the step of causing said operation to be reflected in a summary table.

23. The computer readable medium of claim 18, wherein said sequences of instructions further comprise sequences of instructions for performing the step of defining the trigger for firing when said operation is applied to the said of data, wherein the trigger specifies the series of actions and the trigger-type specific data.

24. The computer readable medium of claim 23, wherein:

the step of defining the trigger includes the step of storing a first reference to first instructions for causing said series of actions to be performed; and

the step of causing said series of actions to be performed based on said trigger-type specific parameters, said operational metadata, and said operational data includes the step of executing said first instructions based on said first reference with said trigger-type specific parameters, said operational metadata, and said operational data passed as parameters.

25. The computer readable medium of claim 23, wherein the step defining the trigger for firing when said operation is applied to said body of data includes the step of defining the trigger for firing when a DML statement is applied to a row of a table.

26. The computer readable medium of claim 23, wherein the step of defining the trigger for firing when said operation is applied to said body of data includes the steps of:

receiving said trigger-type specific data as input from a user; and

storing said trigger-type specific data as metadata associated with said trigger.

28. The computer readable medium of claim 24, wherein the step of storing a first reference to first instructions includes the step of statically linking said first instructions to a database kernel.

29. The computer readable medium of claim 24, wherein the step of storing a first reference to first instructions includes the step of dynamically linking said first instructions to a database kernel.

30. The computer readable medium of claim 24, wherein:

the step of defining a trigger for firing when said operation is applied to said body of data includes the step of

storing a second reference to second instructions for loading trigger-type specific data into run-time memory; and

the step of loading trigger-type specific data as said trigger-type specific parameters includes the step of executing said second instructions based on said second reference.