Optimal use of triggers for detecting database events

• US 7,984,021 B2
• Filed: 12/05/2003
• Issued: 07/19/2011
• Est. Priority Date: 12/05/2003
• Status: Active Grant

• Current Assignee: Domo, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Joshi, Mukul Madhukar, Gupta, Ajay Kumar, Mohania, Mukesh Kumar, Bhide, Manish Anand
• Primary Examiner(s): Abel-Jalil; Neveen
• Assistant Examiner(s): Syed; Farhan M
• Application Number:
  US10/729,166
• Publication Number:
  US 20050125371A1
• Time in Patent Office: 2,783 Days
• Field of Search: 707/1
• US Class Current: 707/662
• CPC Class Codes: G06F 16/2358 Change logging, detection, and notification replication G06F16/27

Abstract

Triggers are dynamically created and destroyed on an application database. Rules are represented in active databases as ECA (event-condition-action) items, in which an action formulates a reaction to an event and is executed after the rule is triggered when the condition is evaluated to true. The event is defined as an instantaneous and atomic (that is, the event either happens completely, or not at all) point of occurrence within an application. Events can be classified as either database, temporal, or user-defined events, and their type can be either primitive or composite.

Claims

1. A method of monitoring events in a database, said method comprising:

storing in said database at least one database rule;

mapping temporal constraints of an event of said database rule to corresponding temporal events;

changing said temporal constraints associated with said temporal events based upon related temporal constraints for related events of said database rule to provide changed temporal constraints;

registering alarms associated with a start and end of a lifespan of each of said temporal events;

selectively deploying and selectively permanently removing ones of said temporal events from said database based upon said changed temporal constraints;

upon reaching said end of said lifespan of each of said temporal events, permanently removing from said database said alarm associated with said ones of said temporal events permanently removed from said database;

combining said temporal events using a sequence operator to form a composite event; and

associating a lifespan to said composite event using said sequence operator.

2. The method as claimed in claim 1, further comprising removing from the database temporal events that cannot evaluate as true.

3. The method as claimed in claim 1, further comprising limiting a lifespan of at least one of said temporal events to an overlapping period of a lifespan of a parent event.

4. The method as claimed in claim 1, further comprising changing a lifespan of one of said temporal events to omit periods in which said one of said temporal events cannot evaluate as true.

5. The method as claimed in claim 1, further comprising assigning a lifespan of at least one of said temporal events having an undefined lifespan as a lifespan of a parent event.

6. The method as claimed in claim 1, further comprising propagating a lifespan or context of a parent node to all children nodes of said parent node.

7. The method as claimed in claim 1, wherein a lifespan of at least one of said temporal events is expressed as a predetermined duration of time.

8. The method as claimed in claim 1, wherein said lifespan of said composite event is dependent upon an associated event.

9. The method as claimed in claim 1, wherein a lifespan of at least one of said temporal events ends at a predetermined time, or recurs at a predetermined period of time.

10. The method as claimed in claim 1, further comprising storing said database rule as an event-condition-action (ECA) rule.

14. The method of claim 1, further comprising using a separate device external to said database to detect said composite event.

15. The method of claim 1, wherein at least one of said temporal events consists of an instantaneous and atomic point of occurrence within an application that affects a state of said database.

11. A database recorded on a non-transitory computer storage medium comprising:

software code means for storing in said database at least one database rule;

software code means for mapping temporal constraints of an event of said database rule to corresponding temporal events;

software code means for changing said temporal constraints associated with said temporal events based upon related temporal constraints for related events of said database rule to provide changed temporal constraints;

software code means for registering alarms associated with a start and end of a lifespan of each of said temporal events;

software code means for selectively deploying and selectively permanently removing ones of said temporal events from said database based upon said changed temporal constraints;

software code means for, upon reaching said end of said lifespan of each of said temporal events, permanently removing from said database said alarm associated with said ones of said temporal events permanently removed from said database;

software code means for combining said temporal events using a sequence operator to form a composite event; and

software code means for associating a lifespan to said composite event using said sequence operator.

12. A system for monitoring events in a database, said system comprising a processor performing a method comprising:

storing in said database at least one database rule;

mapping temporal constraints of an event of said database rule to corresponding temporal events;

changing said temporal constraints associated with said temporal events based upon related temporal constraints for related events of said database rule to provide changed temporal constraints;

registering alarms associated with a start and end of a lifespan of each of said temporal events;

selectively deploying and selectively permanently removing ones of said temporal events from said database based upon said changed temporal constraints;

upon reaching said end of said lifespan of each of said temporal events, permanently removing from said database said alarm associated with said ones of said temporal events permanently removed from said database;

combining said temporal events using a sequence operator to form a composite event; and

associating a lifespan to said composite event using said sequence operator.

13. A non-transitory program storage device medium readable by computer, tangibly embodying a program of instructions executable by said computer to perform a method of monitoring events in a database, said method comprising:

storing in said database at least one database rule;

mapping temporal constraints of an event of said database rule to corresponding temporal events;

changing said temporal constraints associated with said temporal events based upon related temporal constraints for related events of said database rule to provide changed temporal constraints;

registering alarms associated with a start and end of a lifespan of each of said temporal events;

selectively deploying and selectively permanently removing the temporal events from said database based upon said changed temporal constraints;

upon reaching said end of said lifespan of each of said temporal events, permanently removing from said database said alarm associated with said ones of said temporal events permanently removed from said database;

combining said temporal events using a sequence operator to form a composite event; and

associating a lifespan to said composite event using said sequence operator.

16. The non-transitory program storage device medium of claim 13, wherein said method further comprises using a separate device external to said database to detect said composite events.

17. The non-transitory program storage device medium of claim 13, wherein at least one of said temporal events consists of an instantaneous and atomic point of occurrence within an application that affects a state of said database.