The live system is the one that interacts with our customers and must stay up during all business hours which is often 24-7 in today’s global business world. These databases should be designed to collect the data in transactions that are needed to do business. This is often called the Online Transaction Processing database (or OLTP database). This OLTP system must respond immediately to user requests through a proper interface (such as an ATM). During peak business hours the OLTP system can slow down and cause customer delays. If we were to run a query for a business meeting during this peak time we could slow the live system even further. For this reason any testing or analysis is often done on a copy of the database. This way company work and research can get done without interfering with the customer’s usage of the same database.
We have attempted to explain the same subject in simple words over in following video.
Get the book for yourself and your friend. This is just a reference everyone must have it.
Read the related blog post: SQL Basics: Database Careers – Day 7 of 10
Reference: Pinal Dave (http://blog.sqlauthority.com)