Oracle Database 19c: Data Guard Administration Advanced Practice Exam: Hard Questions 2025

Your Data Guard environment consists of a primary database in Maximum Protection mode with two standby databases. During a network partition, the primary database loses connectivity to both standby databases simultaneously. The redo transport is configured with NET_TIMEOUT=30 and REOPEN=60. What will be the behavior of the primary database?

You are troubleshooting a severe performance issue where a physical standby database is lagging 6 hours behind the primary despite having sufficient network bandwidth. Upon investigation, you find that the standby has LOG_ARCHIVE_DEST_1 configured locally and the apply process shows frequent waits on 'log file sequential read'. The alert log shows messages about archive gap resolution. What is the MOST likely root cause and solution?

During a planned switchover operation in a Maximum Availability configuration with Fast-Start Failover enabled, the switchover command completes successfully but the observer immediately initiates an automatic failover back to the original primary. Examination shows that the broker configuration has Configurable Failover Conditions including 'Corrupted Controlfile' and 'Corrupted Dictionary'. What most likely caused this behavior?

Your organization runs a Data Guard environment with a snapshot standby database for testing. After completing tests, you attempt to convert the snapshot standby back to a physical standby, but the conversion fails with ORA-01153: an incompatible media recovery is active. The alert log shows 'Flashback Restore Point does not exist'. The primary database has continued normal operations during the test period. What is the correct recovery procedure?

A financial services company operates a Maximum Performance Data Guard configuration with SYNC redo transport to a local standby and ASYNC transport to a remote standby. During peak trading hours, users report intermittent transaction commit delays of 5-8 seconds. Investigation reveals that the LGWR SYNC process occasionally shows 'LNS wait on SENDREQ' waits, and the network monitoring shows no packet loss but variable latency (2-7ms). The LOG_ARCHIVE_DEST_2 configuration is: 'SERVICE=standby1 SYNC AFFIRM NET_TIMEOUT=30 MAX_FAILURE=0 VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE)'. What is the optimal solution to maintain data protection while eliminating commit delays?

After a complete site failure, you perform an emergency failover to your physical standby database. The failover completes successfully, but when attempting to reinstate the old primary as a new standby, the reinstatement fails with 'ORA-19573: cannot obtain exclusive enqueue for datafile'. The database was using Active Data Guard on the standby before failover, and flashback database was enabled on both databases. What additional step is required before successful reinstatement?

Your Data Guard Broker configuration uses Fast-Start Failover with a configuration that includes one primary and two physical standby databases (STANDBY1 and STANDBY2). The FastStartFailoverTarget property is set to STANDBY1 only. During a primary database failure, the observer is running and detects the failure within the threshold period, but the automatic failover does not occur. Log analysis shows STANDBY1 has a 90-second apply lag, while STANDBY2 is current with zero lag. Both standbys are healthy and synchronized. Why did automatic failover not occur, and what is the best solution?

A multinational corporation has a primary database in New York and a physical standby in London configured with Maximum Performance mode and ASYNC redo transport. The business requires implementing a far sync instance in Chicago to achieve zero data loss protection without impacting primary database commit performance. After configuring the far sync instance with appropriate redo routes, application commits are still experiencing 45ms average latency. Network measurements show 2ms from NY to Chicago and 40ms from Chicago to London. What is the configuration error?

Your environment uses a logical standby database for reporting and read/write operations on non-replicated tables. After applying a primary database DDL change that added a new column with a function-based virtual column, the SQL Apply process stops with ORA-23416: 'Logical standby metadata not supported for table'. The primary table includes system-generated columns, invisible columns, and function-based virtual columns. Flashback database is enabled. What is the most appropriate recovery action that maintains the logical standby functionality?

A Data Guard environment experiences a complete failure of the primary site during a period when the standby database was undergoing maintenance with real-time apply temporarily disabled. The standby has received all archived redo logs but has a 2-hour apply backlog. After performing a failover and opening the new primary with RESETLOGS, you discover that 15 minutes worth of transactions from the old primary were never transmitted due to the failure occurring between log switches. The business requires recovering these transactions. What is the only viable recovery approach?