Zero Downtime Upgrade of Database Applications Using Triggers and Calculated Fields

• US 20160179497A1
• Filed: 12/19/2014
• Published: 06/23/2016
• Est. Priority Date: 12/19/2014
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP SE
• Inventors: Driesen, Volker
• Granted Patent: US 9,501,516 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2379 Updates performed during online database operations; commit processing
• CPC Class Codes: G06F 16/252 between a Database Management System and a front-end application
• CPC Class Codes: G06F 8/65 Updates security arrangements therefor G06F21/57

Abstract

An upgrade of a first version of a database application to a second version of a database application that both have a same data schema is initiated. The first database application has a first access schema such that at least one table in the data schema is linked to the first access schema. The second version of the database application has a second access schema such that at least one table in the data schema is linked to the second access schema. Subsequently, concurrent access is provided for each access schema to at least one database table in the data schema to the first and second versions of the database application. The concurrent access is enabled by a respective at least one table link object in each of the first access schema and the second access schema that is used by database views or stored procedures such access schema.

Claims

1. A method for implementation by one or more data processors forming part of at least one computing device, the method comprising:

initiating an upgrade of a first version of a database application to a second version of a database application that both have a same data schema, the first database application having a first access schema such that at least one table in the data schema is linked to the first access schema, the second version of the database application having a second access schema such that at least one database table in the data schema is linked to the second access schema, the first access schema differing from the second access schema; and

providing, for each access schema, concurrent access to at least one database table in the data schema to both the first version of the database application and the second version of the database application, the concurrent access being enabled by a respective at least one table link object in each of the first access schema and the second access schema that is used by database views or stored procedures such access schema.

2. The method of claim 1 further comprising:

updating, using at least one application trigger associated with at least one table link object, the at least one database table in the data schema to reflect changes in the corresponding table link object.

3. The method of claim 2, wherein there is a first application trigger in the first access schema on the first table link and a second application trigger in the second access schema on a second table link, wherein only the first trigger is called if the table in the data schema is updated through the first table link object in the first access schema and only the second trigger is called if the table in the data schema is updated through the second table link object in the second access schema.

4. The method of claim 1, wherein the at least one table link specifies a select field list of the at least one table in the data schema, wherein the list of fields specified by the table link object is smaller than the list of fields of the table.

5. The method of claim 1, wherein the at least one table link object is used by a database object that cannot use a database view.

6. The method of claim 1, wherein at least one of the table link object specifies a calculated field.

7. The method of claim 6, wherein the calculated field is transient.

8. The method of claim 1, wherein the at least one table link object references a table in the data schema that specifies a calculated field.

9. The method of claim 8, wherein the calculated field is persisted.

10. The method of claim 1, wherein the database application is executed using an in-memory database system.

11. A non-transitory computer program product storing instructions which, when executed by at least one hardware data processors, result in operations comprising:

initiating an upgrade of a first version of a database application to a second version of a database application that both have a same data schema, the first database application having a first access schema such that at least one table in the data schema is linked to the first access schema, the second version of the database application having a second access schema such that at least one database table in the data schema is linked to the second access schema, the first access schema differing from the second access schema; and

providing, for each access schema, concurrent access to at least one database table in the data schema to both the first version of the database application and the second version of the database application, the concurrent access being enabled by a respective at least one table link object in each of the first access schema and the second access schema that is used by database views or stored procedures such access schema.

12. Then non-transitory computer program product of claim 11, wherein the operations further comprise:

updating, using at least one application trigger associated with at least one table link object, the at least one database table in the data schema to reflect changes in the corresponding table link object.

13. The computer program product of claim 12, wherein there is a first application trigger in the first access schema on the first table link and a second application trigger in the second access schema on a second table link, wherein only the first trigger is called if the table in the data schema is updated through the first table link object in the first access schema and only the second trigger is called if the table in the data schema is updated through the second table link object in the second access schema.

14. The computer program product of claim 11, wherein the at least one table link specifies a select field list of the at least one table in the data schema, wherein the list of fields specified by the table link object is smaller than the list of fields of the table.

15. The computer program product of claim 11, wherein the at least one table link object is used by a database object that cannot use a database view.

16. The computer program product of claim 11, wherein at least one of the table link object specifies a calculated field.

17. The computer program product of claim 16, wherein the calculated field is transient.

18. The computer program product of claim 11, wherein the at least one table link object references a table in the data schema that specifies a calculated field.

19. The computer program product of claim 18, wherein the calculated field is persisted.

20. A system comprising:

at least one hardware data processor; and

memory storing instructions which, when executed by the at least one data processor, result in operations comprising;

initiating an upgrade of a first version of a database application to a second version of a database application that both have a same data schema, the first database application having a first access schema such that at least one table in the data schema is linked to the first access schema, the second version of the database application having a second access schema such that at least one database table in the data schema is linked to the second access schema, the first access schema differing from the second access schema; and

providing, for each access schema, concurrent access to at least one database table in the data schema to both the first version of the database application and the second version of the database application, the concurrent access being enabled by a respective at least one table link object in each of the first access schema and the second access schema that is used by database views or stored procedures such access schema.