Ssh connection without password

on client side:

ssh-keygen -t rsa

on server side:
copy the public key from client to home directory that you want to be identified
then

cat id_rsa.pub >> ~/.ssh/authorized_keys

options :
If strict_mode, chmod 600 ~/.ssh/authorized_keys
If Authentication refused : PreferredAuthentications publickey

Export an Oracle database

export ORACLE_SID=INSTANCE_NAME

vi /tmp/export.par

USERID=login_db/pwd_db
LOG=export.log

/oracle/product/10g/bin/exp parfile=/tmp/export.par file=/dump/export.dmp

Create an user on Oracle

launch sqlplus user@INSTANCE

create user $user IDENTIFIED BY $pwd;
grant dba to $user;
create tablespace $user datafile '$dir/${user}.dbf' size 100M autoextend on next 100M;
CREATE TEMPORARY TABLESPACE ${user}TMP TEMPFILE '$dir/${user}tmp.dbf' size 512M autoextend on next 10M;
ALTER USER $user DEFAULT TABLESPACE $user TEMPORARY TABLESPACE ${user}TMP;

How to install Oracle ODBC Client for Cent OS, Fedora or other Redhat products

yum install unixODBC
rpm -ivh oracle-instantclient-basic-10.2.0.3-1.i386.rpm #downloaded on http://www.oracle.com/technology/software/tech/oci/instantclient/htdocs/linuxsoft.html
unzip instantclient-odbc-linux32-10.2.0.3-20061115.zip #downloaded on http://www.oracle.com/technology/software/tech/oci/instantclient/htdocs/linuxsoft.html
cp ./instantclient_10_2/libsqora.so.10.1 /usr/lib/oracle/10.2.0.3/client/lib/
export ORACLE_HOME=/usr/lib/oracle/10.2.0.3/client
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$ORACLE_HOME/lib
mkdir /etc/oracle
vi /etc/oracle/tnsnames.ora

MY_SID =
 ( DESCRIPTION =
  (ADDRESS_LIST =
  (ADDRESS =
  (PROTOCOL = TCP)
  (Host = 127.0.0.1)
  (Port = 1521)
  )
 )
 (CONNECT_DATA = (SID = MY_SID)
 )
)

export TNS_ADMIN=/etc/oracle

vi /etc/odbcinst.ini

[OracleODBC-10g]
Description = Oracle ODBC driver for Oracle 10g
Driver = /usr/lib/oracle/10.2.0.3/client/lib/libsqora.so.10.1
FileUsage = 1
Driver Logging = 7

vi /etc/odbc.ini

[simple]
Driver = OracleODBC-10g
DSN = OracleODBC-10g
ServerName = MY_SID
UserID = USER
Password = PASSWORD

isql -v simple

+---------------------------------------+
| Connected!                            |
|                                       |
| sql-statement                         |
| help [tablename]                      |
| quit                                  |
|                                       |
+---------------------------------------+

Delete a connected user on Oracle

drop user GOAWAY cascade;
return “cannot drop a user that is currently connected”

2 solutions :

• List the session of your user :

  select username, sid, serial# from v$session where lower(username)='GOAWAY';
  alter system kill session '143, 148';

• Restart your instance :

  startup force restrict