Applies to:

Oracle Server - Enterprise Edition - Version: 10.1.0.2 to 10.2.0.3
This problem can occur on any platform.

Symptoms

During switchover from Primary to Physical Standby the following errors occur:

SQL> alter database commit to switchover to physical standby;
alter database commit to switchover to physical standby;
*
ERROR at line 1:
ORA-01093: ALTER DATABASE CLOSE only permitted with no sessions connected 

SQL> select switchover_status from v$database;

SWITCHOVER_STATUS
--------------------
SESSIONS ACTIVE

Checking v$session will show the following:

SQL> select SID, PROCESS, PROGRAM
    2>  from v$session where type = 'USER' and
    3>  SID <> (select DISTINCT SID from v$mystat);

SID       PROCESS    PROGRAM
--------- ---------------- ------------------------------------------------
1078    622624         racgimon@koalav1 (TNS V1-V3)
1079    622624         racgimon@koalav1 (TNS V1-V3)
1080    622624         racgimon@koalav1 (TNS V1-V3)
1086    622624         racgimon@koalav1 (TNS V1-V3)

This error can also occur when any standby database registered with the Oracle Clusterware is being closed.

• ALTER DATABASE CLOSE
• Running RECOVER MANAGED STANDBY DATABASE on a standby that was previously opened in READ ONLY mode

Cause

Oracle Clusterware uses the RAC Global Instance Monitor (racgimon) to monitor instance availability on each node.  In order to close any database, all sessions must be disconnected.

Solution

If the error occurs during switchover in a Data Guard environment, simply re-run the switchover command with the additional clause WITH SESSION SHUTDOWN.

Otherwise stop racgimon using the following command in the database ORACLE_HOME on a single node:

Re-issue the original command that failed.

Starting in Oracle11g Release 1 and up, the racgimon sessions will be ignored on a standby during close.