Storage and File Structure for Computer Science and MCA students
Write short note on File Organization.
There is different database related software available and they provide almost same type of functionality. Database consists of different types of objects such as tables, views, index, procedures, functions etc. The tables and views are logical form of viewing the data. Database is a very huge storage mechanism and the actual data are stored in the physical memory. For accessing these data, any user simply fires the SQL query and the result will come.
These results should come as fast as possible. Simply storing the data in the physical memory will not give the fast result. Todays every organization have huge amount of data/records, which is available in the database. Any user will see these records in the form of tables in the screen. But these records are stored as files in the memory.
To access these files, we need to store them in certain order so that it will be easy and fast to fetch the records. Storing the files in certain order is called file organization. There are various methods of file organizations.
some of the methods are as follows.- Sequential File Organization
- Heap File Organization
- Hash/Direct File Organization
- Indexed Sequential Access Method
- B+ Tree File Organization
1. Sequential File Organization is simple in design and stored or sorted as they come. This method is fast and efficient when there are large volumes of data.
2. Heap File Organization is simplest file organization technique. It is best suited for bulk insertion. Proper memory management technique is required in Heap File Organization.
3. Hash File Organization is two type Static and dynamic. Data is Stored at the hash address. Data access is fast in this technique. It is not gives good result when searching single hash column when multiple hash keys present or frequently updated column as hash key are inefficient.
4. Indexed Sequential Access Method is complex with respect to design. In this technique address index is appended to the record. Searching records is faster and Suitable for large database.
5. B+ Tree File Organization stored the data in a tree like structure. Its design is complex in nature. Searching is very efficient in B+ Tree File Organization technique.
