View a performance evaluation report

Limits

• You can view a performance evaluation report only for a performance evaluation task or an SQL file playback task that is in the Completed state.

• Performance evaluation reports are saved for 15 days.

Procedure

1. Log on to the OceanBase Management Console .

2. In the navigation pane on the left, click Migration Evaluation > Performance Evaluation.

3. On the Performance Evaluation List page, click View Report next to the target evaluation task.

4. On the Workload Playback Report page, view the report details.

Report details

The workload playback report includes the Playback Analysis, Performance Trend, SQL Diagnostic Information, SQL Optimization Information, and Playback Information List modules.

• The Playback Analysis module includes Total Playbacks, Playback Success Rate, and Playback Traffic Comparison Graph. In the upper-right corner of the Playback Traffic Comparison Graph area, you can filter the traffic by the All, Select, or Write type.

  If you filter by All and perform a read-only traffic playback, the source traffic curve includes both read and write traffic. In this case, it is normal for the target curve to be lower than the source curve.

  If you use accelerated playback, the playback time is shorter than the source traffic recording time. The target curve in the playback traffic comparison graph will drop to 0 at the end.

• The Performance Trend module displays line charts for QPS (queries per second), Query Response Time (the average time to process an SQL statement), and CPU Utilization to show performance trends.

• The SQL Diagnostic Information module includes TopSQL and SlowSQL. You can view information such as the SQL text, the accessed database, CPU share, SQL ID, the total number of executions within a specified period, the total execution time (ms), and an error summary. You can also use the quick filter in the upper-right corner of this area.

• The SQL Optimization Information module provides information such as Optimization Type, Tenant, Database, Optimization Object, Diagnostic Reason, and Optimization Suggestion. You can use this information to optimize the related SQL statements.

• The Playback Information List module includes SQL ID, Total Playbacks, SQL Type, and the 90th Quantile of Time Consumed, Median Time Consumed, and Average Time Consumed for both the source and the target.

  The workload playback report from Migration Evaluation aggregates and calculates statistics based on the source SQL ID. In the playback information list, each row represents the statistics for a specific class of SQL during playback. Currently, the workload playback report displays only the top 50 rows of data, sorted in descending order by the number of playbacks.

  Parameter	Description
  SQL ID	An SQL ID represents a class of similar SQL statements and is unique within a specific period. For example: SELECT * FROM TABLEA WHERE COL1 = 1; SELECT * FROM TABLEA WHERE COL1 = 2; The two SQL statements above are considered the same class of SQL and have the same SQL ID. Source SQL ID: The SQL ID from the source logs or calculated by Migration Evaluation. Important If a source SQL statement is truncated, Migration Evaluation calculates a hash value based on the text. In this case, each truncated SQL statement can be considered a separate class of SQL. Target SQL ID: The SQL ID calculated by the OceanBase database.
  Total Playbacks	The total number of times this class of SQL was played back.
  SQL Type	Includes SELECT, INSERT, UPDATE, and DELETE.
  90th Quantile of Time Consumed	The time consumed is measured in milliseconds and is rounded to three decimal places. Assume that this class of SQL was executed n times, with playback times of [x_1,x_2,x_3,....,x_n]. After sorting in descending order, the times are [x_1',x_2',....,x_n']. The P90 value is x'_[n*0.9]. For more information about the function used for calculation, see the approx_percentile function.
  Median Time Consumed	The median calculated from the playback times. The time consumed is measured in milliseconds and is rounded to three decimal places.
  Average Time Consumed	The average value calculated from the playback times. The time consumed is measured in milliseconds and is rounded to three decimal places.

  Migration Evaluation provides two metrics for each executed SQL statement: source execution time and target execution time. The 90th quantile of time consumed, median time consumed, and average time consumed are all aggregated from these two metrics. The sources for the time data are described as follows:

  • Source execution time: This time is obtained directly from SLS. OceanBase and Migration Evaluation cannot guarantee the authenticity of the source execution time or the collection algorithm.

  • Target execution time: This data is obtained from the oceanbase.v$sql_audit view in the OceanBase database.

    Important

    Because of view eviction and the collection speed in the OceanBase database, some target execution time data may be missing.