摘要:
A log-shipping data replication system employs a primary server coupled to a standby server. In operation, the primary server concurrently flushes log data at the primary server and transmits the same log data from the primary server to the standby server. The primary server further transmits at least one buffer flush boundary indication to the standby server indicating the flushing status of the log data at the primary server. The standby server processes the log data as a function of receiving the log data from the primary server, and/or receiving the at least one buffer flush boundary indication from the primary server.
摘要:
A method and system are provided for providing a consistent reintegration of a failed primary instance as a new secondary instance with implementation of truncation of log records. Upon failure of a primary instance, a secondary instance may be reassigned as the new primary instance. Prior to reintegration, any portion of the database log of the failed primary that is after the log position of the new primary instance may be truncated, followed by a comparison of the log positions of both the new primary instance and the new secondary instance. In limited circumstances, the truncation of the log data generated by the failed primary instance after the point of failure is possible, and supports reintegration of the failed primary as a new secondary instance with limited overhead.
摘要:
A method and apparatus for providing efficient space utilization of WORM media while maintaining transactional consistency are disclosed. In response to a transaction, a binary large object (BLOB) associated with the transaction is stored on a staging area of a non-volatile storage medium. A determination is then made as to whether or not a rollback operation needs to be performed on the transaction. If a rollback operation needs not to be performed on the transaction, the BLOB is migrated from the staging area of the non-volatile storage medium to a WORM medium after the transaction has been committed.