DBMS can be used for both of the commercial and non commercial environment just because everybody wants to store the data in some form or the other. If it is in RDBMS, its easier to retrieve the data in better way.

Online UPS is a UPS (uninterrupted power supply) where the ups is directly connected with backup line even when electricity is present and when power goes off, it does not have to switch to the backup so there is very little or no delay to switch over backup power supply. Offline UPS however is different. … Read more

You can use the tools like Microsoft Visio for the purpose. Make sure that you draw it clearly. Most of the ER diagrams are confusing...