control file version 11.2.0.1.0 incompatible with ORACLE version 10.2.0.3.0

SQL*Plus: Release 11.2.0.3.0 Production on Wed May 21 12:16:43 2014

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Connected to an idle instance.

SQL> startup;
ORACLE instance started.

Total System Global Area 2004340736 bytes
Fixed Size                  2256544 bytes
Variable Size            1006633312 bytes
Database Buffers          973078528 bytes
Redo Buffers               22372352 bytes
ORA-00201: control file version 11.2.0.0.0 incompatible with ORACLE version
10.2.0.0.0
ORA-00202: control file: 'D:\ORACLE\GPQ\ORIGLOGA\CNTRL\CNTRLGPQ.DBF'

SQL> show parameter compatible

NAME                                 TYPE
------------------------------------ ---------------------------------
VALUE
------------------------------
compatible                           string
10.2.0
SQL> alter system set compatible='11.2.0.0.0' scope=spfile;

System altered.

SQL> shut immediate;
ORA-01507: database not mounted

ORACLE instance shut down.
SQL> startup;
ORACLE instance started.

Total System Global Area 2004340736 bytes
Fixed Size                  2256544 bytes
Variable Size            1006633312 bytes
Database Buffers          973078528 bytes
Redo Buffers               22372352 bytes
Database mounted.

 

SQL> show parameter compatible

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
compatible                           string      11.2.0.0.0
SQL>