Trigger generation in an active database management system

• US 5,680,602 A
• Filed: 07/17/1996
• Issued: 10/21/1997
• Est. Priority Date: 04/11/1995
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Bloem, Wouter, Bruls, Wiel Angelina Gerardus
• Primary Examiner(s): Kulik, Paul V.
• Application Number:
  US08/683,693
• Time in Patent Office: 461 Days
• Field of Search: 395/601, 395/616, 395/50-52, 395/54, 395/934, 395/676, 395/680, 395/683
• US Class Current: 1/1
• CPC Class Codes: G06F 16/24565 Triggers; Constraints
• CPC Class Codes: Y10S 707/99931 Database or file accessing

Abstract

Triggers for automatically starting an extract process in response to the committing of update data to a repository by an update process. In one embodiment, triggers are associated with particular extract processes and are started upon the committing of update data to the repository by an update process. Upon being started, each trigger determines whether any of the update data is within the extract view of the extract process that it is associated with and, if so, evaluates a predetermined condition specified for the trigger. If the condition is satisfied, the trigger translates the update data within the extract view into the extract view and starts the extract process. In another embodiment, triggers are bound to repository entities within the view of an extract process and are started upon the updating of the corresponding entities. Upon being started, each trigger evaluates a predetermined condition specified for entity post-image and, if the condition is satisfied, adds the post-image to data being accumulated for the extract process. Upon the commitment of the update, all extract processes for which data has been accumulated are started after making available the data accumulated for the process. In yet another embodiment, if the condition specified for the entity post-image is satisfied, the trigger executes a trigger query against the updated entity instance to dynamically generate a list of triggers which are then executed.

Claims

1. In an active database management system in which an update process updates data in a repository and an extract process extracts from said repository data added by said update process, said update process having an update view of data in said repository, said extract process having an extract view of data in said repository that may differ from said update view, a method for automatically starting said extract process in response to the committing of update data to said repository by said update process, said method comprising the steps of:

(a) in response to the committing of update data to said repository by said update process, determining whether any of said update data is within said extract view;

(b) in response to a determination that least some of said update data is within said extract view, evaluating a predetermined condition specified for said extract process; and

(c) in response to an evaluation of said predetermined condition as true, starting said extract process to extract from said repository data added by said update process that is within said extract view.

2. The method of claim 1 in which a plurality of extract processes are defined, said steps (a)-(c) being performed for each of said extract processes.

3. The method of claim 1 in which said step (c) comprises the additional step of translating the update data within said extract view into said extract view.

4. The method of claim 3 in which said step (c) comprises the additional step of making the translated update data available to said extract process.

5. The method of claim 1 in which said predetermined condition is a function of said update data.

6. The method of claim 1 in which said update process performs an update of a selected update type, said predetermined condition being a function of said update type.

7. The method of claim 1 in which said predetermined condition is a function of the preexisting data in said repository.

8. In an active database management system in which an update process updates data in a repository and an extract process extracts from said repository data added by said update process, said update process having an update view of data in said repository, said extract process having an extract view of data in said repository that may differ from said update view, apparatus for automatically starting said extract process in response to the committing of update data to said repository by said update process, said apparatus comprising:

(a) means responsive to the committing of update data to said repository by said update process for determining whether any of said update data is within said extract view;

(b) means responsive to a determination that at least some of said update data is within said extract view for evaluating a predetermined condition specified for said extract process; and

(c) means responsive to an evaluation of said predetermined condition as true for starting said extract process to extract from said repository data added by said update process that is within said extract view.

9. The apparatus of claim 8 in which a plurality of extract processes are defined, said apparatus containing said means (a)-(c) for each of said extract processes.

10. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for automatically starting an extract process in response to the committing of update data to a repository by an update process in an active database management system in which an update process updates data in a repository and an extract process extracts from said repository data added by said update process, said update process having an update view of data in said repository, said extract process having an extract view of data in said repository that may differ from said update view, said method steps comprising:

(a) in response to the committing of update data to said repository by said update process, determining whether any of said update data is within said extract view;

(b) in response to a determination that least some of said update data is within said extract view, evaluating a predetermined condition specified for said extract process; and

(c) in response to an evaluation of said predetermined condition as true, starting said extract process to extract from said repository data added by said update process that is within said extract view.

11. The program storage device of claim 10 in which a plurality of extract processes are defined, said steps (a)-(c) being performed for each of said extract processes.

12. The program storage device of claim 10 in which said step (c) comprises the additional step of translating the update data within said extract view into said extract view.

13. The program storage device of claim 12 in which said step (c) comprises the additional step of making the translated update data available to said extract process.

14. The program storage device of claim 10 in which said predetermined condition is a function of said update data.

15. The program storage device of claim 10 in which said update process performs an update of a selected update type, said predetermined condition being a function of said update type.

16. The program storage device of claim 10 in which said predetermined condition is a function of the preexisting data in said repository.