Overview
OceanBase Database collects a series of SYSSTAT metrics at runtime to reflect the system operating status at a fine granularity. These metrics are one of the core bases for determining database health and are designed to meet diverse O&M needs, including daily monitoring, fault diagnosis, and performance optimization.
Core views
The SYSSTAT metrics of OceanBase Database are stored in a series of dynamic performance views. The main views are as follows:
V$STATNAME view
Provides definitions of all monitorable statistical events (such as name, ID, and class).
V$SESSTAT view
Stores monitoring information at the session level. These values are valid only for the current session and are temporary. When a session disconnects, the corresponding records in the
V$SESSTATview are cleared.V$SYSSTAT view
Stores the cumulative values of all monitoring items since the OBServer instance started. These data are system-level global information and are not cleared when individual sessions disconnect. The data is reset only when the database instance is shut down.
In short, the V$STATNAME view is the foundation for querying and understanding the specific statistical values in views such as V$SYSSTAT and V$SESSTAT. The V$SESSTAT view reflects the activity of a single session, and its lifecycle is consistent with the session. The V$SYSSTAT view reflects the total activity of the OBServer instance since startup, and its lifecycle is consistent with the instance.