SQL SERVER - Backup database script

If you want to make a backup of all your databases, run this script. This script excludes the system databases. Set your backup path accordingly.

DECLARE @name VARCHAR(50) -- database name  
DECLARE @path VARCHAR(256) -- path for backup files  
DECLARE @fileName VARCHAR(256) -- filename for backup  
DECLARE @fileDate VARCHAR(20) -- used for file name

-- specify database backup directory
SET @path = 'E:\backup\'  

-- specify filename format
SELECT @fileDate = CONVERT(VARCHAR(20),GETDATE(),112) 

DECLARE db_cursor CURSOR READ_ONLY FOR  
SELECT name 
FROM master.dbo.sysdatabases 
WHERE name NOT IN ('master','model','msdb','tempdb')  -- exclude these databases

OPEN db_cursor   
FETCH NEXT FROM db_cursor INTO @name   

WHILE @@FETCH_STATUS = 0   
BEGIN   
   SET @fileName = @path + @name + '_' + @fileDate + '.BAK'  
   BACKUP DATABASE @name TO DISK = @fileName  

   FETCH NEXT FROM db_cursor INTO @name   
END   


CLOSE db_cursor   

DEALLOCATE db_cursor

APACHE - Accessing multiple domain names using port 80

If you plan to publish 2 or more domain urls from the same apache server, this configuration will help you but the requirement is the document root path should be different for all domains.

<VirtualHost *:80>
       ServerName my-server1.com
       DocumentRoot /var/www/html/my-app1
    <Directory /var/www/html/my-app1>
Options FollowSymLinks
AllowOverride All
    Require all granted
    </Directory>
</VirtualHost>


<VirtualHost *:80>
       ServerName my-server2.com
       DocumentRoot /var/www/html/my-app2
    <Directory /var/www/html/my-app2>
Options FollowSymLinks
AllowOverride All
    Require all granted
    </Directory>
</VirtualHost>

<VirtualHost *:80>
       ServerName my-server3.com
       DocumentRoot /var/www/html/my-app3
    <Directory /var/www/html/my-app3>
Options FollowSymLinks
AllowOverride All
    Require all granted
    </Directory>
</VirtualHost>

APACHE - Reverse Proxy using root (/)

This took me days to figure out. I am happy to share with you guys who are wondering how to setup a reverse proxy. 

<VirtualHost *:8081>
       ServerName my-server
       DocumentRoot /var/www/html/my-app
       RewriteEngine On
       <Directory /var/www/html/my-app/>
      Options FollowSymLinks
              AllowOverride All
      Require all granted
       </Directory>
ProxyRequests Off
ProxyPreserveHost On

<Proxy *>
Order deny,allow
Allow from all
</Proxy>
ProxyPass / http://{internal-app-server-ip}/
ProxyPassReverse / http://{internal-app-server-ip}/

</VirtualHost>

Save it and restart apache service.

When you access http://my-server:8081 in a browser apache will interpret the configuration above and redirects the url to http://{internal-app-server-ip}/ - internally while preserving the originating url in your browser which is http://my-server:8081. 

APACHE - If application path differs from DocumentRoot

If you are given a requirement where the application path does not reside in the default DocumentRoot defined in the apache config, then do this.

Define your Alias in httpd.conf. This is done in Apache on Windows server which is similar
if you are on Linux server - need to define your path accordingly.

    Alias "/{app-name}" "C:\{app-path}"
    <Directory "C:\{app-path}">
    Require all granted
    </Directory>

Save it and restart apache services. 

APACHE - Redirect URL containing an IP address to domain name

[On]
Red Hat Enterprise Linux Server release 7.4 (Maipo)

Please insert the Rewrite conditions as follows in the .htaccess file located in your DocumentRoot directory.

--- Change the IPs accordingly. ---

<IfModule mod_rewrite.c>
    <IfModule mod_negotiation.c>
        Options -MultiViews
    </IfModule>

    RewriteEngine On

    RewriteCond %{HTTP_HOST} ^10\.24\.19\.85$ [OR]
    RewriteCond %{HTTP_HOST} ^10\.24\.19\.109$
    RewriteRule ^(.*)$ https://{DOMAIN_NAME}/$1 [L,R=301]
</IfModule>

AIX - To clear print queue and restart qdaemon

# enq -sAW

# ps -eaf | grep {queue name}
# kill -9 {queue name}

# cd /var/spool/lpd/qdir
# remove all queues

# cd /var/spool/lpd/stat
# remove the specified queue entry

# stopsrc -s qdaemon
# startsrc -s qdaemon

ORACLE - Kill session

You plan to work on a schema or to drop a schema and Oracle throws you a warning saying Schema is in use. What do you do?

SQL> select sid, serial# from v$session where username='{your-schema}';

Please observe the sid, serial# from the output, then proceed to kill the session with 

SQL> alter system kill session 'sid,serial#';

You can rerun the select statement again to verify the specific schema has been removed.