foreword

　　Doing a good job in daily inspection is an important step in database management and maintenance, and it is necessary to register the date and results of each inspection, and may need to issue an inspection report.

　　This series aims to address some common pitfalls:

I don't know what to check
I don't know how to check easily
Too many machines, check up trouble
Difficulty in generating reports and inability to visualize results

　　Performance is one of the important indicators of the quality of the system, and performance problems may be caused by a small point (such as parameter configuration, job configuration, structural design, software and hardware environment, etc.). The previous seven articles have inspected the system from different aspects. This article will introduce the most important item (performance) in the series of inspections.

performance baseline

　　There are many indicators of performance inspection, and the situation changes greatly, so you should establish a complete performance evaluation model for your own system. What is a performance evaluation model, that is, when the system enters a stable period, after optimization, the system performance A stable value has been reached, then we can use this stable project as a baseline for post-inspection, functional launch, structural changes and other operational performance comparisons.

　　On the [Physical Examination Items] page, we can use a relatively stable historical version of the physical examination item as the performance baseline, which can be renamed as "Performance Baseline" in order to distinguish other items.

Based on performance baseline comparison

　Overall indicator

　　On the [Overview] page, we can view the performance status of the system as a whole, mainly from [Query Statement-Execution Time], [Session-Wait Type], [Check Items], etc., to compare with the baseline. Check whether the indicators in the inspection are significantly different from the baseline indicators.

　　Example: During the inspection, the number of slow statements in each time period in [Query Statement - Execution Time] is significantly higher than the baseline, which means that the statements in the system may become slower. The pressure of system indicators such as CPU, memory, and IO increases, indicating that the pressure on your system has increased. The reason for the increase may be due to newly added unoptimized statements or problems with hardware resources.

　　Note: The collection time of baseline and inspection should be the same or slightly different. If the difference is large, it may not be descriptive.