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Thursday, June 23, 2016

Database Performance Tuning Questionnaire

Performance problems occur when a task takes longer to perform than the time allowed and uses excessive resources. If the database seems to be running very slow or a command seems to take a long time to respond, an experienced DBA can try to diagnose this runtime problem and fix it.
Performance tuning is a complex process requiring collaborative efforts from DBA and Application team. Thus, to make the tuning exercise efficient and minimize the effort required, the performance issues should be clearly defined. The more precise and detailed you can answer below questions, the easier and faster the tuning process will be for a DBA.



Where is the performance issue– describe the type of performance issue in detail
– Issue with just one SQL statement or with a group of SQL
– Issue with just one application function or with a group of functions
– Response time is always slow or during certain time slots only (specify exact time if applicable)
– Provide the time slots with slowest and fastest responses
– Response time is slow on all the relevant databases (production, test etc) or just on one particular database compared to the others (specify relevant DB names with performance comparison)

When is performance issue
– When did the performance issue occur first time (specify precise date and time)?
– Describe the performance issue recurrence
– Are you facing the same issue at the moment?

Why is performance issue
– Were there any changes done just before the issue occurred (describe if any, RFC# etc)
– Have you already taken measures and actions to fix it (describe if any, RFC# etc)?
– What do you think might be a root cause of poor performance?

How much tuning is required – Slow vs Fast
– The amount of performance degradation in % for every affected task
– Acceptable response time for every affected task