1) Ordered file Organization: All file of record are ordered based on some search key value.For searching we use binary search
To access a record ,the avg no of block access =log2B blocks
Advantages: Searching is efficent
Disadvantage: Insertion is expensive due to re organization of the entire file.
2) Unordered file Organization: All file of records are inserted at where ever the place is available useually at the end of thr file.Linear search is used for searching.
To access a record the average no of block access =B/2 block
Advantage: Insertion is efficent
Disadvantage: Searching is inefficent compared to ordered file organisation.