How to import plugin dll for Notepad++?

Dispath the dll file to installation folder of Notepad++ under "plugins" directory.

e.g.
copy ComparePlugin.dll to C:\Program Files (x86)\Notepad++\plugins
then reopen notepad++

How to change NLS paramater?

Check current nls parameter as sys user
SQL> select * from v$nls_parameters;

e.g.
modifying date format parameter

Add below row into init.ora parameter file - apply forever
*.NLS_DATE_FORMAT='DD-MM-YYYY'

Then, restart database.
SQL> shutdown immediate;
SQL> startup;

Run below command - apply just for session
ALTER SESSION SET NLS_DATE_FORMAT = 'DD-MM-YYYY';

Referance: http://docs.oracle.com/cd/A84870_01/doc/server.816/a76966/ch2.htm

How to use existed tns connection for new one?

* The key point is 'Using' keyword that checks tnsnames.ora connection node then you can reach remote database.

SQL> CREATE DATABASE LINK "ALPER_DATABASE_NEW_LINK"
 CONNECT TO hr
 IDENTIFIED BY hr
 USING 'ALPER_DB';

SQL> CREATE DATABASE LINK "ALPER_DATABASE_NEW_LINK2"
 CONNECT TO hr
 IDENTIFIED BY hr
 USING 'ALPER_DB';

SQL> CREATE DATABASE LINK "ALPER_DATABASE_NEW_LINK3"
 CONNECT TO hr
 IDENTIFIED BY hr
 USING 'ALPER_DB';

Oracle escape character examples

First, we need an example data for study.
SQL> insert into departments values ('280','Ad_New',200,1700);

e.g.
SQL> select * from departments where department_name like 'A%';
DEPARTMENT_ID  DEPARTMENT_NAME  MANAGER_ID  LOCATION_ID
10             Administration   200         1700
110            Accounting       205         1700
280            Ad_New           200         1700

SQL> select * from departments where department_name like 'Ad_%';
10             Administration   200         1700
280            Ad_New           200         1700

SQL> select * from departments where department_name like 'Ad/_%' escape '/';
280            Ad_New           200         1700

SQL> select * from departments where department_name like 'Ad__%' escape '_';
280            Ad_New           200         1700

How to gain root access without entering root password on Linux?

Add the line into the end of /etc/sudoers file as root
vi /etc/sudoers
alper ALL=(ALL) NOPASSWD: ALL

Test your connection
ssh alper@10.10.10.10
$ sudo su -
(executes all /etc/profile, .profile and .bashrc files)
# ifconfig
$ sudo su
(executes only .bashrc file)
# ifconfig

References:

• http://askubuntu.com/questions/168461/how-do-i-sudo-without-having-to-enter-my-password
• http://askubuntu.com/questions/376199/sudo-su-vs-sudo-i-vs-sudo-bin-bash-when-does-it-matter-which-is-used

How to define new db link?

Add a new connection node into tnsnames.ora file.
vi $ORACLE_HOME/network/admin/tnsnames.ora
e.g.

ALPER_DB =

  (DESCRIPTION =

    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.10.10.10)(PORT = 1521))

    (CONNECT_DATA =

      (SERVER = DEDICATED)

      (SID = XE )

    ))

Check remote host via tnsping

$ tnsping ALPER_DB

Define a new db link

For specific user:

SQL> CREATE DATABASE LINK "ALPER_DATABASE"

 CONNECT TO hr

 IDENTIFIED BY hr

 USING 'ALPER_DB';

If you desire all users use this link you should add "public" into create statement

For All users (public):

SQL> CREATE PUBLIC DATABASE LINK "ALPER_DATABASE"

 CONNECT TO hr

 IDENTIFIED BY hr

 USING 'ALPER_DB';

Alternative option: define a new db link

For specific user:

SQL> CREATE DATABASE LINK "ALPER_DATABASE"

 CONNECT TO hr

 IDENTIFIED BY hr

 USING '(DESCRIPTION =

    (ADDRESS = (PROTOCOL = TCP)(HOST = 10.10.10.10)(PORT = 1521))

    (CONNECT_DATA =

      (SERVER = DEDICATED)

      (SID = XE )

    ))';

Observe the new link and check it

For specific users:

SQL> select * from user_db_links where db_link = 'ALPER_DATABASE';

SQL> select * from employees@ALPER_DATABASE

For All users (public):

SQL> select * from all_db_links where db_link = 'ALPER_DATABASE';

SQL> select * from employees@ALPER_DATABASE

Extra
Connect without db link:
$ sqlplus "hr@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(Host=10.10.10.10)(Port=1521))(CONNECT_DATA=(SID=XE)))"
or
CMD> sqlplus hr@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(Host=10.10.10.10)(Port=1521))(CONNECT_DATA=(SID=XE)))