What is Connected architecture and Disconnected architecture? Difference between datareader and dataset. What is normalization? What is index? Explain View. What are types of sub-query? what is difference between delete and truncate? what are local and global variables? What is constraint? What is Data Integrity? What is Identity(1,1) means? Explain Self Join. What are user defined functions? What is Recursive stored procedure? Difference between Union and UnionAll.