Introduction of file and file types or organization of file-
In DBMS lots of data saved, That all data used in future for decisions. That all data are saved in physical storage in the computer
File-The file is a collection of related information, In that the all information are stored in the magnetic disk or optical disk.
File Organization-
In file stored information but in file organization information is stored in storage media with different formation. The file organization explain how the file are stored in storage media. The types of file organization is as fallows-
- Sequential File Organization
- Heap File Organization
- Index Sequential File Organization
- Random Access File Organization
That all are used for saving data in different format each of these type differently access data from storage.
1. Sequential File Organization-
It is the simplest method for saving data in sequential file organization. The file is saved as a sequential manner. The data cannot be inserted or accessing into middle of the file. The new data always inserted at the end of the file. If we want 10 number record from sequential file organization then in sequential file organization the first 9 records are search successfully and then reach 10th record.
2. Heap File Organization-
In that method the all records are saved in data blocks. If we want to save a records in a file organization then that record are saved in multiple blocks, If any block is full the new record is stored in any another block but the DBMS can totally responsible for storing that record in block system. There is no sorting or ordering is required for data saving. As compare sequential file organization the heap file organization is faster.
3. Indexed Sequential File Organization-
Indexed sequential file organization work for data saving but the all records are fallow indexed method and that indexed are managed from file management. If user want any record then file management check that record in first in index, If record is found in index then that file searching in sequential file organization. In that method the all records are divided into index format because of that the data searching is easily as compare sequential file organization.
4. Random Access File Organization or Direct Access File Organization-
In that method the new record are inserted or deleted from any location of that file. The new record are also inserted into middle in the file. In Direct Access file or Random Access file organization record Search very easily because the pointer is directly indicated the required file for user. As a heap file organization or sequential file organization the Random Access file is faster for data inserting or accessing from storage.