Storing and using classes in databases

• US 7,941,402 B2
• Filed: 09/24/2004
• Issued: 05/10/2011
• Est. Priority Date: 09/24/2004
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Smits, Thomas
• Primary Examiner(s): Vo; Tim T.
• Assistant Examiner(s): Mobin; Hasanul
• Application Number:
  US10/949,967
• Publication Number:
  US 20060074994A1
• Time in Patent Office: 2,419 Days
• Field of Search: None
• US Class Current: 707/638
• CPC Class Codes: G06F 16/289 Object oriented databases
• CPC Class Codes: G06F 9/44521 Dynamic linking or loading; Link editing at or after load time, e.g. Java class loading
• CPC Class Codes: G06F 9/44536 Selecting among different versions

Abstract

Methods and apparatus, including computer systems and program products, for storing and using, such as classes, in databases. One implementation provides a technique for receiving a specified name, retrieving one or more from a database, and for each resource, one or more attributes associated with the resource, wherein each comprises executable instruction code, and wherein the attributes include a name that matches the specified name. The technique further provides for selecting one of the retrieved based on the attributes associated with each resource, and loading the selected into a runtime system. The attributes may include an archive name, an upload time, a package name, a checksum, a development flag, and/or a user name. By utilizing this technique, end-user or development sessions operative on application servers have the capability to use multiple different versions of classes in runtime environments without interfering with other operative sessions.

Claims

1. A computer-readable storage medium comprising instructions which, when executed, cause a machine to:

create a list of object classes to be deployed into a database by a deployment client over a network;

identify the object classes, wherein the identifying of the object classes further includes identifying a plurality of object class versions associated with the object classes, identifying an oldest user session using an object class of the object classes, and identifying an object class version associated with the object class being used by the oldest user session, wherein the plurality of object class versions includes the object class version, and deleting one or more object class versions whose associated upload time is older than an upload time associated with an object class version that is loaded by the oldest user session;

associate one or more attributes to each of the object classes based on metadata associated with the object classes, and separately store the object classes and the one or more attributes in the database, wherein the one or more attributes to specify object class version information and object class developer information, the one or more attributes are further to specify a special version of the object classes to be accessed and tested in runtime by one or more developers, wherein the one or more attributes comprise a name that matches a specified name;

retrieve the object classes and the one or more attributes from the database;

select a retrieved object class based on the one or more attributes, wherein the selecting includes

determining if a session executing in a runtime system is associated with a developer, and

if the session is associated with the developer, selecting the object class whose development flag is set; and

load the selected object class into a runtime system through a class path to provide a plurality of application servers direct centralized access to the object classes via the database, the database coupled to the plurality of application servers, wherein the class path is to be reused by each of the plurality of application servers each time the application server uses the selected object class.

2. The computer-readable storage medium of claim 1, wherein the runtime system comprises a Java virtual machine or a Common Language Runtime (CLR) virtual machine.

3. The computer-readable storage medium of claim 1, wherein each object class comprises a class.

4. The computer-readable storage medium of claim 1, wherein the attributes associated with each object class further comprise one or more of:

an archive name representing a logical archive with which the object class is associated;

the upload time representing the time at which the object class was stored in the database;

a package name representing a package of which the object class is a part;

a checksum computed on the object class;

the development flag representing whether the object class is a development object class; and

a user name representing a developer to whom the object class belongs.

5. The computer-readable storage medium of claim 4, wherein each object class comprises a class, and wherein the instructions when executed to select one of the retrieved object classes, further cause the machine to:

receive a specification of the class path; and

identify one of the retrieved object classes whose archive name appears first in the class path.

6. The computer-readable storage medium of claim 4, wherein the instructions when executed to select one of the retrieved object classes, further cause the machine to:

receive a specification of a start time associated with a user session executing in the runtime system;

sort the retrieved object classes by the upload time associated with each of the retrieved object classes; and

identify one of the retrieved object classes whose upload time is older than and closest to the start time associated with the user session.

7. The computer-readable storage medium of claim 1, wherein the instructions when executed to select one of the retrieved object classes, further cause the machine to:

receive a specification of a name associated with the session; and

if the session is associated with a developer, identify one or more of the retrieved object classes whose associated user name matches the name associated with the session.

8. The computer-readable storage medium of claim 1, wherein the database stores object classes in a compressed format, and wherein the instructions when executed, further cause the machine to:

decompress the selected object class.

9. The computer-readable storage medium of claim 4, wherein the instructions when executed, further cause the machine to:

use the checksum associated with the selected object class to validate the integrity of the selected object class.

20. The computer-readable storage medium of claim 1, wherein the instructions when executed further cause the machine to:

unpack individual classes in the list from an archive to be deployed individually as a part of a virtual archive in the database by an application server from the plurality of application servers.

21. The computer-readable storage medium of claim 1, wherein the instructions when executed further cause the machine to:

provide a graphical user interface to enable a user to create the list of object classes.

22. The computer-readable storage medium of claim 1, wherein deleting one or more object class versions whose associated upload time is older than the upload time associated with an object class version that is loaded by the oldest user session deletes the one or more object class versions from the database.

10. A method comprising:

creating a list of object classes to be deployed into a database by a deployment client over a network;

identifying the object classes, wherein the identifying of the object classes further includes identifying a plurality of object class versions associated with the object classes, identifying an oldest user session using an object class of the object classes, and identifying an object class version associated with the object class being used by the oldest user session, wherein the plurality of object class versions includes the object class version, and deleting one or more object class versions whose associated upload time is older than an upload time associated with an object class version that is loaded by the oldest user session;

associating one or more attributes to each of the object classes based on metadata associated with the object classes, and separately storing the object classes and the one or more attributes in the database, wherein the one or more attributes to specify object class version information and object class developer information, the one or more attributes are further to specify a special version of the object classes to be accessed and tested in runtime by one or more developers, wherein the one or more attributes comprise a name that matches a specified name;

retrieving the object classes and the one or more attributes from the database;

selecting a retrieved object class based on the one or more attributes, wherein the selecting includes

determining if a session executing in a runtime system is associated with a developer, and

if the session is associated with the developer, selecting the object class whose development flag is set; and

loading the selected object class into a runtime system through a class path to provide a plurality of application servers direct centralized access to the object classes via the database, the database coupled to the plurality of application servers, wherein the class path is to be reused by each of the plurality of application servers each time the application server uses the selected object class.

12. The method of claim 10, wherein the runtime system comprises a Java virtual machine or a Common Language Runtime (CLR) virtual machine.

13. The method of claim 10, wherein each object class comprises a class.

11. An apparatus comprising:

means for creating a list of object classes to be deployed in a database by a deployment client over a network;

means for identifying the object classes, wherein the means for identifying of the object classes further includes means for identifying a plurality of object class versions associated with the object classes, means for identifying an oldest user session using an object class of the object classes, and means for identifying an object class version associated with the object class being used by the oldest user session, wherein the plurality of object class versions includes the object class version, and means for deleting one or more object class versions whose associated upload time is older than an upload time associated with an object class version that is loaded by the oldest user session;

means for associating one or more attributes to each of the object classes based on metadata associated with the object classes, and means for separately storing the object classes and the one or more attributes in the database, wherein the one or more attributes to specify object class version information and object class developer information, the one or more attributes are further to specify a special version of the object classes to be accessed and tested in runtime by one or more developers, wherein the one or more attributes comprise a name that matches a specified name;

means for retrieving the object classes and the one or more attributes from the database;

means for selecting a retrieved object class based on the one or more attributes, wherein the means for selecting includes

means for determining if a session executing in a runtime system is associated with a developer, and

means for selecting the object class whose development flag is set if the session is associated with the developer; and

means for loading the selected object class through a class path into a runtime system to provide a plurality of application servers direct centralized access to the object classes via the database, the database coupled to the plurality of application servers, wherein the class path is to be reused by each of the plurality of application servers each time the application server uses the selected object class.

14. The apparatus of claim 11, wherein the runtime system comprises a Java virtual machine or a Common Language Runtime (CLR) virtual machine.

15. The apparatus of claim 11, wherein each object class comprises a class.

16. A system comprising:

a client coupled to a server;

a database coupled to the client and the server; and

the server in communication with a plurality of application servers, the server to;

receive a list of object classes to be deploy into the database from a deployment client, identify the object classes, wherein the identifying of the object classes further includes identifying a plurality of object class versions associated with the object classes, identifying an oldest user session using an object class of the object classes, and identifying an object class version associated with the object class being used by the oldest user session, wherein the plurality of object class versions includes the an object class version, and delete one or more object class versions whose associated upload time is older than an upload time associated with an object class version that is loaded by the oldest user session,

associate one or more attributes to each of the object classes based on metadata associated with the object classes, and separately store the object classes and the one or more attributes in the database, wherein the one or more attributes to specify object class version information and object class developer information, the one or more attributes are further to specify a special version of the object classes to be accessed and tested in runtime by one or more developers, wherein the one or more attributes comprise a name that matches a specified name,

retrieve the object classes and the one or more attributes from the database,

select a retrieved object class based on the one or more attributes, wherein the selecting includes

determining if a session executing in a runtime system is associated with a developer, and

if the session is associated with the developer, selecting the object class whose development flag is set; and

load the selected object class into a runtime system through a class path to provide a plurality of application servers direct centralized access to the object classes via the database, wherein the class path is to be reused by each of the plurality of application servers each time the application server uses the selected object class.

17. The system of claim 16, wherein the runtime system comprises a Java virtual machine or a Common Language Runtime (CLR) virtual machine.

18. The system of claim 16, wherein each object class comprises a class.

19. The system of claim 16, wherein the attributes associated with each object class further comprise one or more of:

an archive name representing a logical archive with which the object class is associated;

the upload time representing the time at which the object class was stored in the database;

a package name representing a package of which the object class is a part;

a checksum computed on the object class;

the development flag representing whether the object class is a development object class; and

a user name representing a developer to whom the object class belongs.