7.1.9+Access+Speed+&+Storage+Requirements+for+File+Types

=**__Comparison of the Speed of the Access and Storage Requirements for Different File Types__**=

**__Storage Requirements__**

 * Sequential and Direct access files are the same size, however Indexed files require more space because of the storage of the index
 * In a large system the index file could, for 1,000,000 file take up over 10,000,000 Bytes


 * Speed is vitally dependent on:**
 * The Access Time to a Hard Disk
 * The Access Time to read an index file
 * The access Time to read tapes or other forms of media

**__Speed Comparrsion__**

 * **Sequential Access** is the slowest form since it has to read all the data preceding the file that should be accessed. This can mean that all files have to be read if the file required is stored last
 * **Index Access** is faster since it only requires to read the entire index and can then simply skip forward to the file requred.
 * **Record Access**is the potentially fastest but is also affected by the amount of logical records stored in a physical record.
 * This means that the more records are blocked into a physical record, the less time is required to access the required file.

Created by: Daniel Gillo Last modification: 15th September 2011

Sources:
 * Jones, Richard. __Computer Science Java Enabled__. Victoria: IBID Press, 2004