Indexing mechanisms used to speed up access to desired data. An index file consists of records of the form. Hashing is an effective technique to calculate the direct location of a data record on the disk without using index structure. This lecture briefly describe on Indexing and Hashing. Index files are typically much smaller than the original file Two basic kinds of indices: Ordered indices: search keys are stored in sorted order Hash indices: search keys are distributed uniformly across “buckets” using a “hash function”.