Main objective of this lecture is to describe on Indexing and Hashing. An index for a file in a database system works in much the same way as the index in this textbook. If we want to learn about a particular topic, we can search for the topic in the index at the back of the book, find the pages where it occurs, and then read the pages to find the information we are looking for. Here describe two types of indices: Ordered Indices ans Hash Indices. This lecture briefly focus on Primary VS Secondary Indices, Handling of Bucket Overflows etc.