Which two are true about the Oracle database methodology? (Choose two.)
Which two are true about the Oracle database methodology? (Choose two.)
The Oracle Database time model is designed to help identify the areas of the database and instance that require tuning by showing where the database is spending most of its time, making it a reliable method for prioritizing tuning activities. Additionally, tuning activities should be guided by agreed service levels, meaning that once the established performance goals are met, tuning can cease. This ensures that performance is aligned with business objectives and user requirements.
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.
Great explanation, thank you. I personally agree, however, I'm under impression that in some cases, correct answers don't necessarily align with the common sense, but are based in an obscure sentence in the documentation, as here: "The Oracle performance method can be applied until performance goals are met or deemed impractical." https://docs.oracle.com/en/database/oracle/oracle-database/19/tdppt/oracle-database-performance-method.html#GUID-811C438C-149B-4BFE-A40A-1FAF2BF67C95:~:text=The%20Oracle%20performance%20method%20can%20be%20applied%20until%20performance%20goals%20are%20met%20or%20deemed%20impractical.
I doubt that some answers are not offered in good faith, such as option C: "Tuning activities should stop once agreed service levels for performance have been met.". I'm aiming at the "...should..." vs. the "...can..." in the link I gave above.
Agree with AE
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."
I think B instead of C because it mention "feedback from the system users and the people". It's about the people, for example user A may feel that 8mins query is ok instead of current 15 mins query, user B however, may feel 10mins query is acceptable.
Yeah but it also said "the people in charge of the application". I believe that "agreed service levels" is more appropriate, since it sounds similar to a performance "goal". It's quite tricky anyway.
are you sure E? SQL tunned before file system? I am not sure but a file system is not easy to do changes when everything is working
I think wrong queries may destroy best configured file system. I would read this question in this way and answer AE
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
It's AE. Tuning is an ongoing process.
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.
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.
NIEMNkaoguolema
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 (...).
https://docs.oracle.com/en/database/oracle/oracle-database/19/tdppt/oracle-database-performance-method.html#GUID-6203E485-FA06-4EE3-9003-4449FBDE214B
A,C 100% sure
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.
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
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
I guess that correct answers are A and C.