delete database and configure database options in DBCA greyed out (disabled) I am using oracle 11g R2 on Linux Redhat 6.3 and  created a lot of databases. At that time there was no problem. But currently I am seeing that in DBCA (Database Configuration Assistant) application some options are disabled as follows:-

1 Create  a Database - ENABLED

2 Configure Database Options - DISABLED

3 Delete a Database  - DISABLED

4 Manage Templates - ENABLED

I don't understand why this happening but in starting all the options were enabled.

EDIT :

oratab file content, inside etc/oratab

**

# This file is used by ORACLE utilities.  It is created by root.sh
# and updated by the Database Configuration Assistant when creating
# a database.
# A colon, ':', is used as the field terminator.  A new line terminates
# the entry.  Lines beginning with a pound sign, '#', are comments.
#
# Entries are of the form:
#   $ORACLE_SID:$ORACLE_HOME:&lt;N|Y&gt;:
#
# The first and second fields are the system identifier and home
# directory of the database respectively.  The third filed indicates
# to the dbstart utility that the database should , "Y", or should not,
# "N", be brought up at system boot time.
#
# Multiple entries with the same $ORACLE_SID are not allowed.
#
#
Dev:/oracle11gr2/u01/app/oracle/product/11.2.0/db_1:N
Stage:/oracle11gr2/u01/app/oracle/product/11.2.0/db_1:N
Test:/oracle11gr2/u01/app/oracle/product/11.2.0/db_1:N
qa1:/oracle11gr2/u01/app/oracle/product/11.2.0/db_1:N
Dev2:/oracle11gr2/u01/app/oracle/product/11.2.0/db_1:N
Qual:/oracle11gr2/u01/app/oracle/product/11.2.0/db_1:N
fStage:/oracle11gr2/u01/app/oracle/product/11.2.0/db_1:N


**
DBCA relies on /etc/oratab. If that file is empty, or the entry for the database you want to delete is missing, the option(s) will be disabled.