Exam 1z0-083 topic 1 question 32 discussion

AE i suppose

Few differences of opinions here. I believe that A is definitely correct. It will show what the database is spending most time on, that (usually) indicates where tuning is required. B and C relate to user experience. We (DBAs) should work with users, to help achieve their requirements. However, we can be proactive outside of this. Just because a user is happy - doesn't mean we can't make them "happier" by doing tuning activities before things get bad. So, neither of these should be true. D is incorrect, memory is much less likely to be a culprit of an issue, than a filesystem I/O issue. E is correct. We should never try to tune a file system first. If we make a file system change that fixes one SQL statement - it might harm a different SQL statement. However, if we tune the first SQL statement, it will have no impact on the rest of the system. Therefore, we should try to tune "bad SQL" first. F is incorrect - the alert log gives us little/no information to do with tuning. So, AE are correct.

Following oracle tuning methodology for tuning from top to bottom, E is correct and D is wrong. B and C are almost the same and very tricky. Although oracle methodology is to stop tuning when a goal is reached, but this goal shouldn't be just a SLA or a satisfied user as the goal can be beyond that. A is definitely correct, while F is wrong as alert.log is irrelevant to performance tuning.

The Oracle Database time model should be used to find the database and instance areas most in need of tuning. SQL statements should always be tuned before tuning any file systems.

I guess that correct answers are A and C.

A. https://docs.oracle.com/en/database/oracle/oracle-database/19/tdppt/oracle-database-performance-method.html#GUID-8DEA5079-6AAB-47D8-857A-9B5301843290 C. https://docs.oracle.com/en/database/oracle/oracle-database/19/tdppt/oracle-database-performance-method.html#GUID-6203E485-FA06-4EE3-9003-4449FBDE214B

AC is right tunning should be based on agreed SLA see https://docs.oracle.com/en/database/oracle/oracle-database/19/tdppt/oracle-database-performance-method.html#GUID-D5B54332-FE40-4537-B1C9-0704343CEF54

The two true statements about the Oracle database methodology are: A. The Oracle Database time model should be used to find the database and instance areas most in need of tuning. C. Tuning activities should stop once agreed service levels for performance have been met. Why not E? E. While tuning SQL statements is an important aspect of Oracle database performance tuning, it is not necessary to tune SQL statements before tuning any file systems. Again, the order of tuning activities may depend on the specific needs of the system.

A,C 100% sure

https://docs.oracle.com/en/database/oracle/oracle-database/19/tdppt/oracle-database-performance-method.html#GUID-6203E485-FA06-4EE3-9003-4449FBDE214B

A: time model gives the best view of how the instance spends its time. E: Unless the instance configuration is totally off, the SQL statement tuning has the greatest performance benefit.

Because of the same reason as Asmodeus: 1. This feedback makes it easier to set performance goals. Improved performance can be measured in terms of business goals rather than system statistics (...) 2. (...) The Oracle performance method can be applied until performance goals are met or deemed impractical (...).

NIEMNkaoguolema

The alert log and trace files are vital in instance tuning. They may point you to the problem (memory bottlenecks, locked sessions): - End to End Application tracing identifies excessive workloads on the system by specific user, service, or application component. - Server-generated alerts automatically provide notifications when impending problems are detected. See Oracle Database Administrator's Guide to learn how to monitor the operation of the database with server-generated alerts.

It's AE. Tuning is an ongoing process.

I think A y B. D and E can be wrong because they said ALWAYS and even in most of the case you will tune the instance and the SQL, maybe there is some weird cases where you see the issue is with the I/O and you start tunning first the File Systems

I guess that correct answers are A and C. C because of documentation: https://docs.oracle.com/en/database/oracle/oracle-database/19/tdppt/oracle-database-performance-method.html#GUID-6203E485-FA06-4EE3-9003-4449FBDE214B: "Before looking at database or operating system statistics, it is crucial to get feedback from the system users and the people in charge of the application. This feedback makes it easier to set performance goals. Improved performance can be measured in terms of business goals rather than system statistics. The Oracle performance method can be applied until performance goals are met or deemed impractical."