Isolation level on the active standby database

The only isolation level that is supported on an active standby database (an HADR standby database that is read enabled) is Uncommitted Read (UR). If the isolation level requested by an application, statement, or sub-statement is higher than UR, an error will be returned (SQL1773N Reason Code 1).

If you require an isolation level other than UR, consider using the HADR primary instead of the standby for this application. If you simply want to avoid receiving this message, set the DB2_STANDBY_ISO registry variable to UR. When DB2_STANDBY_ISO is set to UR, the isolation level will be silently coerced to UR. This setting takes precedence over all other isolation settings such as statement isolation and package isolation.