Providing continuous database access during database modification

Patent metadata

Field	Value
Publication number	US-9471659-B2
Application number	US-201213730756-A
Country	US
Kind code	B2
Filing date	Dec 28, 2012
Priority date	Mar 6, 2012
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

The subject matter described herein relates to providing a continuous access to a database at times, including when the database is being modified or upgraded. Initially, access to an old version of a table is enabled and provided to a user. A copy of the old version is generated. Access is asynchronously redirected from the old version to the copy of the old version. A new version of the table is generated by modifying the structure of the first version of the table. The copy of the old version is accessible when the database is being modified or upgraded. When the structure is being modified, access is asynchronously redirected from the copy of the old version to the new version.

First claim

What is claimed is:

1. A non-transitory computer program product storing instructions that, when executed by at least one programmable processor, cause the at least one programmable processor to perform operations comprising:
enabling at least one of a read access and a write access to a first version of a table;
generating a copy of the first version of the table, a structure of the copy of the first version of the table being same as a structure of the first version of the table;
redirecting, on a first user-by-user basis, access from the first version of the table to the copy of the first version of the table, the first user-by-user basis characterizing a provision of continuous access for a user to the first version of the table until a first transaction performed by the user is completed, the first user-by-user basis being associated with the completion of the first transaction when the user has not been assigned authentication information;
generating a second version of the table by modifying the structure of the first version of the table, the copy of the first version of the table being accessible when the updating is being performed; and
redirecting, when the structure of the first version of the table is being modified and on a second user-by-user basis, access from the copy of the first version of the table to the second version of the table, the second user-by-user basis characterizing a provision of continuous access for the user to the copy of the first version of the table until a second transaction performed by the user is completed, the second user-by-user basis being associated with the completion of the second transaction when the user has not been assigned authentication information.

2. The computer program product of claim 1 , wherein the table is a database.

3. The computer program product of claim 1 , wherein the redirecting of the access from the first version of the table to the copy of the table comprises:
performing a first set of one or more changes in the copy of the first version of the table in response to the first set of one or more changes directly performed in the first version of the table; and
preventing performing of a second set of one or more changes in the first version of the table in response to the second set of one or more changes directly performed in the copy of the first version of the table.

4. The computer program product of claim 3 , wherein the first set of one or more changes includes at least one of: direct insertions of data, direct updates of data, and direct deletions of data that are performed in the first version of the table.

5. The computer program product of claim 3 , wherein second set of one or more changes includes at least one of: direct insertions of data, direct updates of data, and direct deletions of data that are performed in the copy of the first version of the table.

6. The computer program product of claim 3 , wherein the preventing is performed by at least one semantic lock.

7. The computer program product of claim 1 , wherein the first user-by-user basis characterizes a provision of continuous access for each user to the first version of the table until re-authentication information is received from a user to access the table, the first user-by-user basis being associated with the re-authentication information when the user has been assigned authentication information, the re-authentication being received based on a desire of the user.

8. The computer program product of claim 7 , wherein access to the copy of the first version of the table is enabled and provided to the user after the re-authentication information is received from the user.

9. The computer program product of claim 1 , wherein redirecting of the access from the copy of the first version of the table to the second version of the table comprises:
performing a third set of one or more changes in the second version of the table in response to the third set of one or more changes directly performed in the copy of the first version of the table; and
preventing performing of a fourth set of one or more changes in the copy of the first version of the table in response to the fourth set of one or more changes directly performed in the second version of the table.

10. The computer program product of claim 9 , wherein the third set of one or more changes includes at least one of: direct insertions of data, direct updates of data, and direct deletions of data that are performed in the copy of the first version of the table.

11. The computer program product of claim 9 , wherein the fourth set of one or more changes includes at least one of: direct insertions of data, direct updates of data, and direct deletions of data that are performed in the second version of the table.

12. The computer program product of claim 9 , wherein the preventing is performed by at least one semantic lock.

13. The computer program product of claim 1 , wherein the second user-by-user basis characterizes a provision of continuous access for each user to the copy of the first version of the table until re-authentication information is received from a user to access the table, the second user-by-user basis being associated with the re-authentication information when the user has been assigned authentication information, the re-authentication being received based on a desire of the user.

14. The computer program product of claim 13 , wherein access to the second version of the table is enabled and provided to the user after the re-authentication information is received from the user.

15. The computer program product of claim 1 , causing the at least one programmable processor to perform operations further comprising:
deleting the copy of the first version of the table after all users have been redirected from the copy of the first version of the table to the second version of the table.

16. The computer program product of claim 1 , causing the at least one programmable processor to perform operations further comprising:
deleting the first version of the table after all users have been redirected from the copy of the first version of the table to the second version of the table.

17. The computer program product of claim 1 , wherein the first version of the table, the copy of the first version of the table, and the second version of the table are configured to be accessed via internet.

18. The computer program product of claim 1 , wherein the table is provided on a server computer that is accessed over a communication network by a plurality of client computers in a client-server architecture, each client computer being operated by one or more users.

19. A method comprising:
enabling, using at least one processor, at least one of a read access and a write access to a first version of a database;
generating, using at least one processor, a copy of the first version of the database, a structure of the copy of the first version of the database being same as a structure of the first version of the database;
asynchronously redirecting, using at least one processor and upon completion of a first transaction, access from the first version of the database to the copy of the first version of the database;
generating, using at least one processor, a second version of the database by modifying the structure of the first version of the database, the copy of the first version of the database being accessible when the updating is being performed; and
asynchronously redirecting, using at least one processor and when the structure of the first vers

Assignees

• Driesen Volker
• Jordt Nicolai
• Mayer Martin
• Hoprich Wieland
• Engelko Andrey
• Meissner Steffen
• Schreiber Peter
• Bentzien Levke
• Sap Se

Inventors

• Driesen Volker
• Jordt Nicolai
• Mayer Martin
• Hoprich Wieland
• Engelko Andrey
• Meissner Steffen
• Schreiber Peter
• Bentzien Levke

Classifications

• G06F17/30578 Primary

  Physics · mapped topic

• G06F12/16

  Protection against loss of memory contents {(contains no material, see G06F11/00)} · CPC title

• G06F17/303

  Physics · mapped topic

• G06F17/30091

  Physics · mapped topic

• G06F16/214 Primary

  Database migration support · CPC title