AWR – Buffer Hit Ratio – Analysis
What is Buffer Hit ratio OR Buffer Hit %? ‘Buffer Hit Ratio’ is measured by the percentage of times the data block is requested by the query and available in memory. It is also called…
AWR – Execute to Parse Ratio – Analysis
What is Execute to Parse ratio OR Execute to Parse %? Every query needs to be parsed before it gets executed. If some queries are quite frequently used, a good design will be to reuse…
AWR – Instance Efficiency Percentages
In AWR, the ‘Instance Efficiency Percentages’ table comes under the ‘Report Summary’ section. Refer to the below figure: The following metrics are available in the ‘Instance Efficiency Percentages’ table of an AWR report: Buffer Nowait…
AWR – Load Profile
In AWR, the Load Profile table comes under the ‘Report Summary’ section. Refer to the below figure: The following metrics are available in the Load Profile table of an AWR report: DB Time(s) DB Time(s)…
Performance Engineering Interview Questions #13
Following are the Performance Engineering Interview Questions Set #13. Q. 61 How can lock contention be identified in an AWR report? Ans: High wait events like “enq: TX- row lock contention” or “enq: TM- contention”…
Performance Engineering Interview Questions #12
Following are the Performance Engineering Interview Questions Set #12. Q. 56 What role does the buffer cache play in database performance? Ans: The buffer cache stores copies of data blocks read from the disk. A…