Summary
The arc_event table in MySQL is not in InnoDB, access to it is not automatic. A little preparation is required.

Products
ArcSight Enterprise Security Manager (ESM)

Environment
ArcSight ESM (CORR-Engine based) 6.x and 7.x all versions

Situation
When selecting event data from arc_event table in MySQL, following error is shown.
mysql> select event_id, name from arc_event limit 10;
ERROR 3232 (HY000): 5005: invalid user session: [20]
mysql>

Cause
The arc_event is not stored by the InnoDB of mysql. Instead, it is stored on a different storage engine designed by ArcSight.
To do such kind of query, it is needed to first get sessionId and then set this sessionId in MySQL, followed by running the query.

Read Full Knowledge Base Article here for Resolution steps. 

URL Name
KM000014211l