Synchronization of database data

• US 20020161769A1
• Filed: 04/25/2001
• Published: 10/31/2002
• Est. Priority Date: 04/25/2001
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Piispanen, Jussi, Mettala, Riku, Sutinen, Ari, Sahinoja, Mikko
• Granted Patent: US 6,839,564 B2
• Time in Patent Office: Days
• US Class Current: 707/10
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users

Abstract

A method of arranging synchronization of databases, the method comprising the steps of establishing a transport layer connection for synchronization between a first and a second device which synchronize databases. During initialization of synchronization a first update identifier, which is stored at least in the first device and describes the latest synchronization event the devices have performed in the databases, and a second update identifier, which is defined by the first device and describes the present synchronization, are transmitted from the first device to the second device. The second update identifier is stored in the first and the second device. The contents of the first update identifiers stored in the devices are updated in the first and the second device if synchronization has been performed and after this said transport layer connection has been ended substantially properly.

Claims

1. A method of arranging synchronization of databases, the method comprising the steps of:

establishing a transport layer connection for synchronization between a first and a second device which synchronize databases,

transmitting a first update identifier, which is stored at least in the first device and describes the latest synchronization event the first and the second device have performed in the databases, during initialization of synchronization from the first device to the second device, and a second update identifier, which is defined by the first device and describes the present synchronization,

storing said second update identifier in the first device and in the second device, and

updating the contents of the first update identifiers stored in the devices with the contents of said second update identifier in the first device and in the second device if synchronization has been performed and after this said transport layer connection has been ended substantially properly.

2. A method according to claim 1, which further comprises the steps of:

comparing the first update identifier received in the second device with the first update identifier stored in the second device,

performing synchronization in the requested manner if the first received update identifier corresponds to the first stored update identifier,

synchronizing all data units of the databases if the first received update identifier does not correspond to the first stored update identifier.

3. A method according to claim 2, which further comprises the steps of:

transmitting the first stored update identifier from the second device to the first device,

comparing also the first received update identifier with the first stored update identifier in the first device.

4. A method according to claim 1, wherein

the update identifiers indicate the date and time.

5. A method according to claim 1, wherein

synchronization is based on a synchronization protocol according to the SyncML standard, the first update identifier being the Last anchor of synchronization and the second update identifier the Next anchor.

6. A method according to claim 1, wherein

said transport layer connection is a logical connection in accordance with the HTTP protocol, and

said transport layer connection has been ended properly if a ‘

HTTP request’

message has been transferred between the first device and the second device after synchronization and a ‘

HTTP status response’

message related to the ‘

HTTP request’

message has been transmitted and received.

7. A synchronization system for synchronizing databases comprising a first device and a second device which perform synchronization and are arranged to

establish a transport layer connection between the first device and the second device for performing synchronization,

transmit a first update identifier, which is stored at least in the first device and describes the latest synchronization event the first and the second device have performed in the databases, from the first device to the second device during initialization of synchronization and a second update identifier, which is defined by the first device and describes the present synchronization,

store said second update identifier, and

update the contents of the first update identifiers stored in the devices with the contents of said second update identifier if synchronization has been performed and after this said transport layer connection has been ended substantially properly.

8. A synchronization system according to claim 7, wherein

the second device is arranged to compare the first update identifier received with the first update identifier stored in the second device,

the first and the second device are arranged to perform synchronization in the requested manner if the first received update identifier corresponds to the first stored update identifier, or

the first device and the second device are arranged to synchronize all data units of the databases if the first received update identifier does not correspond to the first stored update identifier.

9. A telecommunications device comprising

means for establishing a transport layer connection to at least one other device for synchronizing databases,

means for transmitting a first update identifier and a second update identifier defined by said telecommunications device to the other device during initialization of synchronization, the first update identifier being stored at least in said telecommunications device and describing the latest synchronization event said telecommunications device and the other device have performed in the databases, and said second update identifier describing the present synchronization,

means for storing said second update identifier, and

means for updating the contents of the first update identifier stored in said telecommunications device with the contents of said second update identifier if synchronization has been performed and after this said transport layer connection has been ended substantially properly.

10. A synchronization device comprising

means for establishing a transport layer connection to at least one other device for synchronizing databases,

means for receiving a first update identifier and a second update identifier from the other device during initialization of synchronization, the first update identifier describing the latest synchronization event said synchronization device and the other device have performed in the databases, and the second update identifier describing the present synchronization,

means for storing said second update identifier, and

means for updating the first update identifier with the contents of said second update identifier if synchronization has been performed and after this said transport layer connection has been ended substantially properly.

11. A synchronization device according to claim 10, which also comprises

means for comparing the first update identifier received with the first update identifier stored in said synchronization device,

means for performing synchronization in the manner requested by the other device if the first received update identifier corresponds to the first stored update identifier, and

means for synchronizing data units of all databases if the first received update identifier does not correspond to the first stored update identifier.

12. A computer program product loadable into the memory of a telecommunications device and comprising a code which is executable in the telecommunications device making the telecommunications device

establish a transport layer connection to at least one other device for synchronizing databases,

transmit a first update identifier and a second update identifier defined by said telecommunications device to the other device during initialization of synchronization, the first update identifier being stored at least in said telecommunications device and describing the latest synchronization event said telecommunications device and the other device have performed in the databases, and said second update identifier describing the present synchronization,

store said second update identifier, and

update the contents of the first update identifier stored in said telecommunications device with the contents of said second update identifier if synchronization has been performed and after this said transport layer connection has been ended substantially properly.

13. A computer program product loadable into the memory of a computer functioning as a synchronization device and comprising a code which is executable in the synchronization device making the synchronization device

establish a transport layer connection to at least one other device for synchronizing databases,

receive a first update identifier and a second update identifier from the other device during initialization of synchronization, the first update identifier describing the latest synchronization event said synchronization device and the other device have performed in the databases, and the second update identifier describing the present synchronization,

store the second update identifier, and

update the contents of the first update identifier stored in said synchronization device with the contents of said second update identifier if synchronization has been performed and after this said transport layer connection has been ended substantially properly.