International Business Machines Corporation

Dilip Kumar Biswal

Isaac Kam-Chak Cheng

Donald Lee Clare

Louis S W Mau

Cecilia O Chu

Cecilia Oi-Lin Chu

Stephen Andrew Brodsky

Paul Arnold Ostler

Anshul Dawra

David Joseph Wisneski

William Robert Bireley

Swaminathan Gounder

Delmar Eugene Blevins

Manish Sehgal

Catalina Y Wei

Systems, methods and articles of manufacture are disclosed for batching heterogeneous database commands. The heterogeneous database commands may include at least two database command types. Further, at least two of the heterogeneous database commands may include host variables. A request to execute the heterogeneous database commands may be received. The heterogeneous database commands may be sent to a database system for execution, responsive to the request.

Batching heterogeneous database commands

A system for efficient snapshot querying include: providing a first version value for each data in a history table, where the first version value indicates a beginning of a period in which the data is valid; providing at least a second version value for each data in the history table, where the second version value indicates an end of the period in which the data is valid; receiving a request for a version of a database; and retrieving the data with the first version value less than or equal to the requested version and the second version value greater than or equal to the requested version. By maintaining a history table with redundant version information, the system is able to provide efficient snapshot querying while also avoiding the overhead burden of conventional approaches. No aggregates, joins, or sub-queries are required to retrieve a snapshot.

Redundant version information in history table that enables efficient snapshot querying

A system for synchronizing data on a first device with data at a second device, includes: determining a pre-image of the data on the first device according to a filter after a previous synchronization with the data at the second device; determining a current image of the data at the second device according to the filter; determining a delta of the current image, where the delta comprises data that exists in the current image and has changed since the previous synchronization; instructing the first device to delete data that exists in the pre-image but not in the current image; and instructing the first device to UPSERT a union of the data that exists in the delta and the data that exists in the current image but not the pre-image. This is efficient in time and bandwidth resources while also providing consistent data integrity.

Incrementally sychronizing occasionally-connected mobile databases, preserving horizontal filter scope consistency by using client pre-image

A method and system for efficient snapshot querying include: providing a first version value for each data in a history table, where the first version value indicates a beginning of a period in which the data is valid; providing at least a second version value for each data in the history table, where the second version value indicates an end of the period in which the data is valid; receiving a request for a version of a database; and retrieving the data with the first version value less than or equal to the requested version and the second version value greater than or equal to the requested version. By maintaining a history table with redundant version information, the method and system are able to provide efficient snapshot querying while also avoiding the overhead burden of conventional approaches. No aggregates, joins, or sub-queries are required to retrieve a snapshot.

A method and system for synchronization-replication concurrency maintain a history table for a data table in a mirror, where the history table can include redundant version values that indicate a period in which data values corresponding to the version values are valid. Replication can thus be performed between a source and a mirror for a current version of the data table, while synchronization is simultaneously performed between the mirror and a client for an earlier version of the data table using the history table.

Synchronization-replication concurrency using non-shared snapshot query on a history table at read-uncommitted isolation level

A method for synchronizing data on a first device with data at a second device, includes: determining a pre-image of the data on the first device according to a filter after a previous synchronization with the data at the second device; determining a current image of the data at the second device according to the filter; determining a delta of the current image, where the delta comprises data that exists in the current image and has changed since the previous synchronization; instructing the first device to delete data that exists in the pre-image but not in the current image; and instructing the first device to UPSERT a union of the data that exists in the delta and the data that exists in the current image but not the pre-image. This is efficient in time and bandwidth resources while also providing consistent data integrity.

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Union City, CA, United States of America

Dilip Kumar Biswal