Which two would you recommend to avoid this error?

Your Data Guard environment consists of these components and settings:
1. A primary database
2. A remote physical standby database
3. Real-time query is enabled.
4. The redo transport mode is set to SYNC.5. The protection mode is set to Maximum Availability.
You notice that queries executed on the physical standby database receive errors:
ORA- 03172: STANDBY_MAX_DATA_DELAY of 15 seconds exceeded.
Which two would you recommend to avoid this error?

Your Data Guard environment consists of these components and settings:
1. A primary database
2. A remote physical standby database
3. Real-time query is enabled.
4. The redo transport mode is set to SYNC.5. The protection mode is set to Maximum Availability.
You notice that queries executed on the physical standby database receive errors:
ORA- 03172: STANDBY_MAX_DATA_DELAY of 15 seconds exceeded.
Which two would you recommend to avoid this error?

A.
Change the protection mode to Maximum Performance.

B.
Increase the size of the buffer cache on the standby database instance.

C.
Reduce I/O latency for the storage used by the primary database.

D.
Change the protection mode to Maximum Protection.

E.
Increase the network bandwidth between the primary and standby databases.

F.
Increase the number of standby redo log files on the primary database.

Explanation:
A: Maximum Performance
This protection mode provides the highest level of data protection that is possible without affecting the
performance of a primary database. This is accomplished by allowing transactions to commit as soon as all
redo data generated by those transactions has been written to the online log. Redo data is also written to one
or more standby databases, but this is done asynchronously with respect to transaction commitment, so
primary database performance is unaffected by delays in writing redo data to the standby database(s).
E: Increasing the bandwidth would decrease the lag.
Note: If STANDBY_MAX_DATA_DELAY is set to a non-zero value, a query issued to a physical standby
database will be executed only if the apply lag is less than or equal to STANDBY_MAX_DATA_DELAY.
Otherwise, an ORA-3172 error is returned to alert the client that the apply lag is too large.

https://docs.oracle.com/cd/B28359_01/server.111/b28294/protection.htm
http://docs.oracle.com/html/E26088_02/statements_2013.htm



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Chunn

Chunn

C and E are correct.

Though changing protection mode to MaxPerformance will put it in ASYNC mode it doesn’t seems to be an appropriate solution as the database is using real time query and it will defeat the purpose. Technically Primary and Standby switches logs at the same time, for this reason it is recommended to created them with the same size (and +1 log for standby logs). For this reason tuning network and I/O performance is going to help.

Ahmed Fouad

Ahmed Fouad

If you are working with MaxPerformance mode you can enable real time query no problem about that.so i think choosing MaxPerformance may be correct answer also.what do you think?

Chunn

Chunn

Yes you can. However, it will change redo transport to ASYNC.