File Organisation & Access

Serial Files

Serial files are files that are designed to be read record by record, with each record being processed in turn

Data is not necessarily organized, though it is often appended to sequentially in real time and it therefore sometimes chronological.

 

 

 

 

Sequential Files

Sequential files have to be read in order, just like serial files, however when using sequential files you  are often looking to access a particular record that has been stored. The program traverses the file until it reaches the desired record, it then returns that record for further use/processing.

 

Direct Access Files

Direct access files are files where the data does not need to be read in order, instead data can be read directly from a particular point in a file. This makes access far more efficient, especially with larger files that are thousands or millions of lines long.

 

 

Resources

Hash Tables

Exam Past Paper Questions

May 2015 paper 31 Qn 7

May 2016 paper 31 Qn4

May 17 paper 31 qn4