F452 File handling

Serial file:

• Data is stored in the order that it is added.
• This is known as 'appending' the data.

Sequential file:

• Data is stored according to a key field.
• When writing data to a sequential file all subsequent records need to be moved.
• File modes:
• -Append
• -Create
• -CreateNew
• -OpenOrCreate
• -Read
• -ReadWrite
• -Write

Indexed sequential file:

• Data is arranged according to a key field but uses an index which can find records directly.

Random files:

• Allow data to be stored anywhere in a dedicated section of a disk.
• A hash algorithm (calculation) is performed on a field in the record to be stored.

Size estimation:

1.  Determine the size in Bytes of each field.
2.  Add the field sizes.
3.  Multiply by number of records.
4.  Add 10% to the result for additional storage/ overhead.