While shutting down my TEST database process was hanged. Then I had to use shutdown abort. But when I wanted to start database it did not open.
 SQL> select name from v$database;  
 NAME  
 ---------  
 TESTSQL> shut abort;  
 ORACLE instance shut down.  
 SQL> startup mount  
 ORACLE instance started.  
 Total System Global Area 6597406720 bytes  
 Fixed Size                2265664 bytes  
 Variable Size           3204451776 bytes  
 Database Buffers       3372220416 bytes  
 Redo Buffers            18468864 bytes  
 Database mounted.  
 SQL> alter database open;  
 alter database open  
 *  
 ERROR at line 1:  
 ORA-03113: end-of-file on communication channel  
 Process ID: 6552  
 Session ID: 191 Serial number: 3  SQL> alter database open resetlogs;  
 ERROR:   
 ORA-03114: not connected to ORACLE  
SQL> exit
Disconnected from Oracle Database 11g Enterprise Edition
Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real
Application Testing options
And instance got down
$ ps -ef | grep smon
oracle    6586  6246  0 17:50
pts/2    00:00:00 grep smon
 $ sqlplus "/as sysdba"  
 SQL*Plus: Release 11.2.0.4.0 Production on Mon Dec 26 17:50:35 2016  
 Copyright (c) 1982, 2013, Oracle. All rights reserved.  
 Connected to an idle instance.  
 SQL> startup mount  
 ORACLE instance started.  
 Total System Global Area 6597406720 bytes  
 Fixed Size                2265664 bytes  
 Variable Size           3204451776 bytes  
 Database Buffers       3372220416 bytes  
 Redo Buffers            18468864 bytes  
 Database mounted.  
Tried to reset logs
SQL> alter database open resetlogs;  
 alter database open resetlogs  
 *  
 ERROR at line 1:  
 ORA-01139: RESETLOGS option only valid after an incomplete database recovery SQL> recover database until cancel;  
 Media recovery complete.  
Now, try to open with resetlogs
 SQL> alter database open resetlogs;  
 Database altered. 
Done, now it works
 
