New Features for Administrators - Question 082

In the Oracle9i Data Guard architecture, what is the purpose of the Log Transport Services?

A. To transfer redo log information to one or more destinations

B. To apply redo log records sent from the primary database to a standby database at the receiving location

C. To synchronize changes to the control files on all standby databases with changes on the primary database when a log switch occurs

D. To batch archived log files on the primary database until a defined number of checkpoints have been processed and then to distribute the archives to each standby database

Answer: A

Explanation:

The Log Transport Service is comprised of several processes. On the primary database site, the Log Writer updates the online redo logs with the transactions. It can also update the local archived redo logs and send online redo logs transactions to the standby databases. The Archiver saves the online redo log transactions on either local or standby archive logs. The Fetch Archive Log (FAL) client gets redo log transactions from the primary database. When it detects an archive log gap on the standby database, it initiates a request to the FAL server to automatically send and archive the primary database’s redo log transactions. The FAL server exists on the primary database server, and it services requests from FAL clients.

Incorrect Answers

B: The Log Application Service applies the archived redo logs to the standby database.

C: Log Transport Services cannot synchronize changes to the control files on all standby databases with changes on the primary database when a log switch occurs

D: They do not batch archived log files on the primary database.

OCP Oracle9i Database: New Features for Administrators, Daniel Benjamin, p. 51-74 Chapter 2: Availability Enhancements

Oracle 9i New Features, Robert Freeman, p. 86-99 Chapter 3: New Oracle9i Availability and Recoverability Features