Performance Logging settings control how Mini DBA writes query and performance diagnostic logs from the connected engine. Use this page to set storage limits and decide when expensive query plans should be captured.
Fields
- Log Folder: optional folder for performance log output. Leave blank to use the engine default. If you set an explicit path, use a folder valid for the engine host, such as
/var/lib/minidba-engine/Logson Linux or containers,C:\ProgramData\MiniDBA Engine\Logson Windows, or%HOME%\site\data\minidba-engine\Logson Azure App Service. - Max Total Logs Storage (Mb): maximum total storage used by performance logs.
- Individual Log Max Size (Mb): maximum size of a single log file.
- Log Execution Plan When Query Exceeds (Seconds): threshold for collecting an execution plan for slow queries.
Recommended Use
Keep enough log history to troubleshoot recurring problems, but set limits that protect the engine host from unbounded disk growth. If you lower the slow-query threshold, Mini DBA may capture more diagnostic detail and write more data.
Workflow
- Open Settings.
- Select Performance Logging.
- Enter log folder and storage limits.
- Set the execution plan capture threshold.
- Save.
- Review Service Log if logging does not behave as expected.
Performance Logging Guidance
Performance logging is most useful when you need evidence for recurring slow queries or support investigations. Keep enough history to compare incidents, but set storage limits that protect the Mini DBA Engine host. The log folder should be on storage that has enough capacity and is included in your operational backup or retention plan if required.
Execution plan capture can be valuable, but lowering the threshold too far may capture more data than needed. Start with a threshold that catches genuinely slow statements, then adjust based on the workload and storage impact. If a production system has sensitive query text, confirm retention and access policies before increasing diagnostic capture. For plan review workflows, see Execution Plan Analysis.
When logs appear missing, check the configured path, service account file permissions, storage limits, and Service Log.
Performance Logging FAQ
Should I capture execution plans for every query?
No. Capture plans for queries that exceed a meaningful threshold to avoid noise and storage growth.
Where should logs be stored?
Use a reliable local or approved path that the engine service account can write to and operations can monitor. For Linux or container engines, use a mounted path such as /var/lib/minidba-engine/Logs or another approved persistent mount. For Windows engines, use a service-account writable path such as C:\ProgramData\MiniDBA Engine\Logs or another operations-managed drive. For Azure App Service, use a persistent path such as %HOME%\site\data\minidba-engine\Logs.
What happens when storage limits are reached?
Mini DBA should limit log storage according to the configured values. Review service logs if retention does not behave as expected.