Real-time database update transaction with disconnected relational database clients

• US 20060010178A1
• Filed: 08/15/2005
• Published: 01/12/2006
• Est. Priority Date: 07/01/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Wilmot, Gerald J.
• Granted Patent: US 7,287,044 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A method and system for performing real-time database update transactions with disconnected database clients includes a disconnected client server (DCS) and disconnected client extensions (DCE). The DCS formats the database cell, its key, any associated database cells, and a timestamp and sends them to a disconnected database client by email. The timestamp indicates the last time the database cell or associated database cells was changed. The disconnected database client sends a reply email with the update of the database cell and the timestamp. Upon receipt of the reply email, the DCS compares the received timestamp to a current timestamp for the database cell. If they match, then the database cell is updated according to the received update. If they do not match, then the update is based on outdated information and is rejected. In this manner, reliable real-time update transactions are provided between a disconnected database client and the database.

Claims

1. A method for performing real-time update transactions between a database and disconnected database clients, comprising the steps of:

(a) sending an update request for a data from a database system to a client, wherein the update request comprises a timestamp for the data, wherein the timestamp indicates a last time the data was changed, wherein the client is disconnected from the database system;

(b) receiving an update and the timestamp for the data from the disconnected database client;

(c) determining if the received timestamp matches a current timestamp for the data; and

(d) updating the data according to the received update, if the timestamp of the received update matches the current timestamp for the data, wherein the client is disconnected from the database during the updating.

2. The method of claim 1, wherein the client and the database system communicate via email.

3. The method of claim 2, wherein the update request is comprised in an email.

4. The method of claim 1, wherein the update request comprises:

an updatable column data set (UCDS), wherein the UCDS comprises;

a database cell,

associated database cells;

a synchro timestamp checksum value (STCV), wherein the STCV comprises;

the timestamp, wherein the timestamp indicates a last time the database cell or the associated database cells was changed, and

a checksum for the database cell; and

a key for the UCDS.

5. The method of claim 2, wherein the received update and the received timestamp are comprised in a reply email.

6. The method of claim 1, wherein the received timestamp does not match the current timestamp, if the data was changed since the update request was created.

7. The method of claim 4, wherein the sending step (a) comprises:

(a1) creating the UCDS and the STCV by the database,

(a2) receiving by a disconnected client server (DCS) a message to request an update of the database cell;

(a3) retrieving the database cell and the associated database cells of the UCDS, the key, and the STCV from the database;

(a4) formatting the database cell and the associated database cells, the key, and the STCV for an email request by the DCS; and

(a5) sending the email request to the disconnected database client.

10. The method of claim 4, wherein the receiving step (b) comprises:

(b1) receiving a reply email from the disconnected database client by the DCS, wherein the reply email comprises the update of the database cell and the STCV.

11. The method of claim 4, wherein the determining step (c) comprises:

(c1) determining if the STCV in the reply email from the disconnected database client matches a current STCV of the database cell by the DCS, wherein the reply email further comprises the update.

12. The method of claim 4, wherein the updating step (d) comprises:

(d1) sending the update of the database cell to the database, if the STCV in the reply email from the disconnected database client matches the current STCV of the database cell; and

(d2) updating the database cell and the current STCV according to the update by the database.

13. The method of claim 4, further comprising:

(e) rejecting the update of the database cell, if the STCV in the reply mail from the disconnected database client does not match the current STCV of the database cell.

8. (canceled)

9. (canceled)

14. A method for performing real-time update transactions between a database and disconnected database clients, comprising the steps of:

(a) creating a UCDS and a STCV by the database, wherein the UCDS comprises a database cell and associated database cells, wherein the STCV comprises a timestamp and a checksum for the UCDS, wherein the timestamp indicates a last time the database cell or the associated database cells was changed;

(b) receiving by a DCS a message to request an update of the database cell;

(c) sending the email request to the disconnected database client, wherein the email request comprises the database cell and the associated database cells, a key for the UCDS, and the STCV at a time the email request was created;

(d) receiving a reply email from the disconnected database client by the DCS, wherein the reply email comprises the update of the database cell and the STCV;

(e) determining if the STCV in the reply email matches a current STCV of the UCDS by the DCS;

(f) sending the update of the database cell to the database, if the STCV in the reply email matches a current STCV of the UCDS; and

(g) updating the database cell and the current STCV according to the update by the database, wherein the client is disconnected from the database during the updating.

15. A computer readable medium with program instructions for performing real-time update transactions between a database and disconnected database clients, comprising the instructions for:

(a) sending an update request for a data cell from a database system to a client, wherein the update request comprises a timestamp for the data, wherein the timestamp indicates a last time the data was changed at a time the update request was created, wherein the client is disconnected from the database system;

(b) receiving an update and the timestamp for the data from the disconnected database client;

(c) determining if the received timestamp matches a current timestamp for the data; and

(d) updating the data according to the received update, if the timestamp of the received update matches the current timestamp for the data, wherein the client is disconnected from the database during the updating.

16. The medium of claim 15, wherein the client and the database system communicate via email.

17. The medium of claim 16, wherein the update request is comprised in an email.

18. The medium of claim 15, wherein the update request comprises:

an UCDS, wherein the UCDS comprises;

a database cell,

associated database cells;

a STCV, wherein the STCV comprises;

the timestamp, wherein the timestamp indicates a last time the database cell or the associated database cells was changed, and

a checksum for the database cell; and

a key for the UCDS.

19. The medium of claim 16, wherein the received update and the received timestamp are comprised in a reply email.

20. The medium of claim 15, wherein the received timestamp does not match the current timestamp for the data, if the database record has been changed since the update request was created.

21. The medium of claim 18, wherein the sending instruction (a) comprises:

(a1) creating the UCDS and the STCV by the database;

(a2) receiving by a DCS a message to request an update of the database cell;

(a3) retrieving the database cell and associated database cells of the UCDS, the key, and the STCV from the database;

(a4) formatting the database cell and the associated database cells, the key, and the STCV for an email request by the DCS; and

(a5) sending the email request to the disconnected database client.

24. The medium of claim 18, wherein the receiving instruction (b) comprises:

(b1) receiving a reply email from the disconnected database client by the DCS, wherein the reply email comprises the update of the database cell and the STCV.

25. The medium of claim 18, wherein the determining instruction (c) comprises:

(c1) determining if the STCV in the reply email from the disconnected database client matches the current STCV of the database cell by the DCS, wherein the reply email further comprises the update.

26. The medium of claim 18, wherein the updating instruction (d) comprises:

(d1) sending the update of the database cell to the database, if the STCV in the reply email from the disconnected database client matches the current STCV of the database cell; and

(d2) updating the database cell and the current STCV according to the update by the database.

27. The medium of claim 18, further comprising instructions for:

(e) rejecting the update of the database cell, if the STCV in the reply mail from the disconnected database client does not match the current STCV of the database cell.

22. (canceled)

23. (canceled)

28. A computer readable medium with program instructions for performing real-time update transactions between a database and disconnected database clients, comprising the instructions for:

(a) creating a UCDS and a STCV by the database, wherein the UCDS comprises a database cell and associated database cells, wherein the STCV comprises a timestamp and a checksum for the UCDS, wherein the timestamp indicates a last time the database cell or the associated database cells was changed;

(b) receiving by a DCS a message to request an update of the database cell;

(c) sending the email request to the disconnected database client, wherein the email request comprises the database cell and the associated database cell, a key for the UCDS, and the STCV at a time the email request was created;

(d) receiving a reply email from the disconnected database client by the DCS, wherein the reply email comprises the update of the database cell and the STCV;

(e) determining if the STCV in the reply email matches a current STCV of the UCDS by the DCS;

(f) sending the update of the database cell to the database, if the STCV in the reply email matches a current STCV of the UCDS; and

(g) updating the database cell and the current STCV according to the update by the database, wherein the client is disconnected from the database during the updating.

29. A system, comprising:

a database, comprising disconnected client extensions (DCE), wherein the database utilizes the DCE;

to create an UCDS comprising a data,

to create a timestamp for the UCDS, wherein the timestamp indicates a last time the data was changed, and

to update the data and the timestamp when an update is received from the database server; and

the database server, comprising a disconnected client server (DCS), wherein the DCS sends an update request comprising the data and the timestamp to a client, wherein the client is disconnected from the database server, wherein the DCS receives the update and the timestamp from the update request from the disconnected database client,

wherein the DCS sends the received update to the database if the received timestamp matches a current timestamp for the UCDS, wherein the data is updated by the database according to the update, wherein the client is disconnected from the database during the update.

32. The system of claim 29, wherein the received timestamp does not match the current timestamp if the data was changed since the update request was created.

30. (canceled)

31. (canceled)

33. (canceled)

34. A database server, comprising:

a connection to a database, the database comprising a UCDS, the UCDS comprising a data; and

a DCS, wherein the DCS creates an update request for the data, wherein the update request comprises the data, a key for the UCDS, and a timestamp, wherein the timestamp indicates a last time the data was changed,

wherein the DCS receives an update for the data from a client, wherein the update comprises the timestamp from the update request, wherein the client is disconnected from the database server,

wherein the DCS sends the received update to the database if the received timestamp matches a current timestamp for the data, wherein the data is updated according to the update, wherein the client is disconnected from the database server during the update.