Zero downtime upgrade of database applications using triggers and calculated fields

• US 9,501,516 B2
• Filed: 12/19/2014
• Issued: 11/22/2016
• Est. Priority Date: 12/19/2014
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP SE
• Inventors: Driesen, Volker
• Primary Examiner(s): APONTE, FRANCISCO JAVIER
• Application Number:
  US14/576,558
• Publication Number:
  US 20160179497A1
• Time in Patent Office: 704 Days
• Field of Search: 717/169, 707609-831
• 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 the database application that both have a same data schema, the first version of the database application having a first access schema comprising a first table link object linking to a database table in the data schema to the first access schema, the first table link object specifying a transient calculated field that is not persisted in the database table in the data schema, the transient calculated field being defined on the first table link object and not on the database table in the data schema such that changing of calculated field logic for the transient calculated field in the upgrade proceeds without requiring copying of the database table; and

creating a second access schema for the second version of the database application, the second access schema comprising a second table link object linking the database table in the data schema to the second access schema, the first access schema differing from the second access schema, the first access schema and the second access schema providing concurrent access to the database table in the data schema to the first version of the database application via the first access schema and to the second version of the database application via the second access schema, the first table link object being consumable by one or more first database objects in the first access schema and acting as a first view to the database table in the data schema, and the second table link object being consumable by one or more second database objects in the second access schema and acting as a second view to the database table in the data schema.

2. The method of claim 1, wherein the first table link object specifies a select field list of the database table in the data schema, wherein the select field list specified by the table link object is smaller than a list of fields of the database table.

3. The method of claim 1, wherein the first table link object is used by a database object that cannot use a database view.

4. The method of claim 1, wherein the first table link object references a table in the data schema that specifies a calculated field.

5. The method of claim 4, wherein the calculated field is persisted.

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

7. The method of claim 1, further comprising:

deploying a first application trigger active in the first access schema and a second application trigger active in the second access schema, the first application trigger being associated with the first table link object and the second application trigger being associated with the second table link object.

8. The method of claim 7, further comprising:

firing the first application trigger only when the first table link object is updated and the second application trigger only when the second table link object is updated, the firing of the first application trigger causing the first table link object to update the database table to add a new field without cloning the database table in the data schema.

9. 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 the database application that both have a same data schema, the first version of the database application having a first access schema comprising a first table link object linking to a database table in the data schema to the first access schema, the first table link object specifying a transient calculated field that is not persisted in the database table in the data schema, the transient calculated field being defined on the first table link object and not on the database table in the data schema such that changing of calculated field logic for the transient calculated field in the upgrade proceeds without requiring copying of the database table; and

creating a second access schema for the second version of the database application, the second access schema comprising a second table link object linking the database table in the data schema to the second access schema, the first access schema differing from the second access schema, the first access schema and the second access schema providing concurrent access to the database table in the data schema to the first version of the database application via the first access schema and to the second version of the database application via the second access schema, the first table link object being consumable by one or more first database objects in the first access schema and acting as a first view to the database table in the data schema, and the second table link object being consumable by one or more second database objects in the second access schema and acting as a second view to the database table in the data schema.

10. The computer program product of claim 9, wherein the first table link object specifies a select field list of the database table in the data schema, wherein the select field list specified by the table link object is smaller than a list of fields of the database table.

11. The computer program product of claim 9, wherein the first table link object is used by a database object that cannot use a database view.

12. The computer program product of claim 9, wherein the first table link object references a table in the data schema that specifies a calculated field.

13. The computer program product of claim 12, wherein the calculated field is persisted.

14. The non-transitory computer program product of claim 9, wherein the operations further comprise:

deploying a first application trigger active in the first access schema and a second application trigger active in the second access schema, the first application trigger being associated with the first table link object and the second application trigger being associated with the second table link object.

15. The non-transitory computer program product of claim 14, wherein the operations further comprise:

firing the first application trigger only when the first table link object is updated and the second application trigger only when the second table link object is updated, the firing of the first application trigger causing the first table link object to update the database table to add a new field without cloning the database table in the data schema.

16. 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 the database application that both have a same data schema, the first version of the database application having a first access schema comprising a first table link object linking to a database table in the data schema to the first access schema, the first table link object specifying a transient calculated field that is not persisted in the database table in the data schema, the transient calculated field being defined on the first table link object and not on the database table in the data schema such that changing of calculated field logic for the transient calculated field in the upgrade proceeds without requiring copying of the database table; and

creating a second access schema for the second version of the database application, the second access schema comprising a second table link object linking the database table in the data schema to the second access schema, the first access schema differing from the second access schema, the first access schema and the second access schema providing concurrent access to the database table in the data schema to the first version of the database application via the first access schema and to the second version of the database application via the second access schema, the first table link object being consumable by one or more first database objects in the first access schema and acting as a first view to the database table in the data schema, and the second table link object being consumable by one or more second database objects in the second access schema and acting as a second view to the database table in the data schema.