java.sql.SQLException: ORA-01033: ORACLE initialization or shutdown in progress DSRA0010E: SQL State = 08006, Error Code = 1,033

Sometimes , we come across this exception and are not able to connect to the corresponding schema -

java.sql.SQLException: ORA-01033: ORACLE initialization or shutdown in progress

DSRA0010E: SQL State = 08006, Error Code = 1,033

The actual error can be something else -

ORA-00600: internal error code, arguments: [kcratr1_lastbwr], [], [], [], [],
[], [], []

We can find it out by using the following steps -

SQL> select status from v$instance;

the result should be MOUNTED. If so, try
SQL> alter database open;

This will give the actual error. If the error is this -

ORA-00600: internal error code, arguments: [kcratr1_lastbwr], [], [], [], [],
[], [], []

Then follow these steps to fix it -

SQL> startup mount;

Database mounted.

SQL> recover database;

Media recovery complete.

SQL> alter database open;

Database altered.

This should fix the issue.