International Business Machines Corporation

Xiang Wei Zhou

Xiao Li

Serge Bourbonnais

Jonathan W Wierenga

Hong Min

Xin Wu

Yat On Lau

Austin F M D'Costa

Christian Zentgraf

Several replication subscriptions are defined for a table in a database management system. The table is divided into partitions. Each replication subscription replicates transactions to a range of partitions. Subscriptions are assignable to different consistency groups. Transaction consistency is preserved at the consistency group level. A persistent delay table is created for each of several apply functions. Each apply function processes replication subscriptions for one consistency group, to replicate the table to a target table in parallel. Transactions for a given range of a partition are executed in parallel. When an apply function upon a row of the target table results in an error, the row is stored in the delay table. Application of each row in the delay table is repeatedly retried, and if successful, the row is removed from the delay table.

Parallel replication of data table partition

A system, method and computer program product for enabling light weight table comparison with high-accuracy (high confidence) of tables where one is a copy of the other, which copy may be maintained synchronized by replication. The method performs database comparison using a sample-based, statistics-based, or materialized query tables-based approaches. The method first identifies a block comprising a sub-set of rows of data of a source database table and a corresponding block from a target database table, and obtains a statistical value associated with each block. Then the statistical values for the corresponding source and target block are compared and a consistency evaluation of source and target database is determined based on comparing results. Further methods enable a determination of the data as being persistent or not in manner that accounts for real-time data modifications to underlying source and target database tables while identified blocks are being compared.

Lightweight table comparison

Growing community of inventors

Shanghai, China

Xiang Wei Zhou