1. Code DescriptionColourSelling PriceNo. Sold C105MattPrimrose£9.00 4 C106MattLilac£9.00 6 C120SilkPrimrose£9.00 4 C121SilkLilac£9.00 2 C123SilkPlum£9.00 0 C124MattMagnolia£7.00 7 C125MattJade£7.00 6 1.

2. 2. a).Describe and give a be a use for each Transaction File A transaction file is a temporary file used to store data, which will be used to update the master file. Examples Bank transactions for a day Employees hours worked for a week Master File A master file is the main file for an application - a large file of semi-permanent data. Examples Bank Customers Employees

3. 2. b) Draw a diagram that illustrates the organisation of each type of file Serial File A serial file is one in which the records have been stored in the order in which they have arisen. They have not been sorted into any particular order. 7 Sequential File A sequential file is one in which the records are stored in sorted order of one or more key fields. Key Data 2 1 4 5 1 st Rec 2 nd Rec4 th Rec 3 rd Rec 5 th Rec 1 Key Data 2 4 5 7 1 st Rec 2 nd Rec4 th Rec 3 rd Rec 5 th Rec

4. c) Outline using a diagram and at least 4 stages how a transaction file could be used to update a master file The 1 st record from the sorted transaction file is read The 1st record from the old master file is read These are compared: If the Old master file record < the transaction record Copy it to the new master file unchanged The next record from the old master file is read If the Old master file record < the transaction record Copy it to the new master file unchanged If the Old master file record = the transaction record Update the record and then copy it to the new master file Unsorted Sort

5. 3. Describe using a diagram and notes how a large sequential file is backed up Sequential files uses a Grandfather - Father - Son method of back up. This is also called generations of files. The Old Master Files and corresponding transactions are kept for several generations. (kept securely at a different site) If a disaster occurs and current data is lost it can be recreated by using the safely stored previous generation data (Old Master file and Transactions) Grandfather Son Father Store Safely