" Sparse Index"
In this an index record appears for only some of the "Search key values.
To locate a record, we find the index entry with the largest search key value that is less than or equal to the search-key value for which we are looking.
We start at the record pointed to by that index entry, and follow the pointers in the file until we find the desired record.
If we want to search 'Film City new " record then what will happen?
• 1) it will be fast track the end up with this search key value if not found.
• 2) Then search key for the largest search key value which less than or equal to the Film City.
In this case it will point to DC block's starting record and we move down side to search our search-key record.
Advantages of Sparse Indexing:
• It Require Less Space
• It requires Less maintenance overhead for Insertion and Deletion operation.
