Emulation of empty database tables using database views

• US 7,702,696 B2
• Filed: 04/16/2007
• Issued: 04/20/2010
• Est. Priority Date: 04/16/2007
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Ziegler, Torsten, Haas, Frank-Martin
• Primary Examiner(s): Le; Uyen T.
• Application Number:
  US11/787,617
• Publication Number:
  US 20080256118A1
• Time in Patent Office: 1,100 Days
• Field of Search: None
• US Class Current: 707/803
• CPC Class Codes: G06F 16/22 Indexing; Data structures therefor; Storage structures
• CPC Class Codes: G06F 16/284 Relational databases

Abstract

Methods and a system for managing database usage. The methods and system include receiving a request to create a table, determining the table is an empty table, and storing a pseudo-table in a data store in response to determining the table is empty. The pseudo-table may be a database view. Metadata related to a table may be stored in the pseudo-table to describe characteristics of the table. The pseudo-table occupies less space than a corresponding empty table. The system may implement the methods in middleware transparent to the applications.

Claims

1. A method comprising:

receiving a request to create a table;

determining whether the table is an empty table; and

storing a pseudo-table in a data store in response to determining the table to be empty, the pseudo-table stored in place of the table by a middleware implemented by a computer system.

2. The method of claim 1, wherein the pseudo-table is a database view.

3. The method of claim 1, further comprising:

storing metadata with the pseudo-table to describe characteristics of the table.

4. The method of claim 3, wherein the metadata includes a table creation command.

5. The method of claim 3, wherein the metadata includes characteristics of data objects related to the table.

6. The method of claim 3, wherein the metadata describes an index, triggers, or check constraints related to the table.

7. A method comprising:

intercepting a database command from an application by a middleware implemented by a computer system, the database command to access a table that is stored as a pseudo-table the pseudo-table stored in place of the table;

returning a result of the database command to the application.

8. The method of claim 7, further comprising:

generating a table in response to intercepting the database command, the database command to modify the table.

9. The method of claim 7, further comprising:

returning an indication that data is not found to the application in response to intercepting the database command, the database command to delete or update data.

10. The method of claim 7, further comprising:

modifying a definition of the pseudo-table in response to intercepting the database command, the database command to modify a structure of the table.

11. The method of claim 7, further comprising:

determining whether an error message received in response to execution of the database command is caused by the pseudo-table.

12. The method of claim 7, wherein the pseudo-table is a database view.

13. A system comprising:

a data store to store a plurality of tables and pseudo-tables; and

a processor and memory to provide an application and middleware, the application to utilize the plurality of tables and the middleware to manage pseudo-table and table creation and to store a pseudo-table in place of a table transparent to the application to conserve space in the database.

14. The system of claim 13, wherein the middleware intercepts and processes results of database commands to manage the pseudo-table and table creation.

15. The system of claim 13, wherein the middleware manages pseudo-table and table creation for the application transparently.

16. A machine readable medium having a set of instructions stored therein which when executed cause a machine to perform a set of operations comprising:

receiving a request to modify a table in a data store;

checking for a pseudo-table stored in place of the table in the data store;

retrieving a pseudo-table definition; and

modifying the pseudo-table definition to reflect a modification to the table.

17. The machine readable medium of claim 16, having a further set of instructions stored therein which when executed cause a machine to perform a set of operations further comprising:

modifying the pseudo-table definition to indicate a property of an object related to the table.

18. The machine readable medium of claim 17, wherein the object is any one of an index, trigger or check constraint related to the table.

19. The machine readable medium of claim 16, wherein the pseudo-table is a database view.

20. The machine readable medium of claim 16, having a further set of instructions stored therein which when executed cause a machine to perform a set of operations further comprising:

deleting the pseudo-table after generating a corresponding table.