File operations are the different things that can be done to a computer file.

The main types of file operation are searching, sorting, updating and merging.

Searching

Searching, or interrogating a file, involves looking for an individual record or group of records that match a certain condition.

Searches are also called queries.

To search a database the user must enter a query. The query tells the software which fields to look at in each record and what to look for.

Sorting

Sorting involves putting the records in a file into a particular order, such as alphabetical order.

Merging

Merging involves combining two files to produce one new file. This can be done by merging a file of new records to be added with another file that contains all of the existing records — called the master file.

Updating

The information stored in computer files must be kept up-to-date or it will cause problems for the business or organisation that’s using it.

To keep a file up-to-date it must be regularly updated. This involves inserting, deleting and amending records.

When a new record needs to be added to a file, it is inserted. Records are deleted when they are no longer needed. Records are amended when the data in one or more of the fields needs to be altered for some reason.

Details of all the changes that need to be made to a master file are often collected together in a transaction file.

The master file is updated by comparing it with the transaction file and making changes to any records that appear in both files. Normally at least three ‘generations’ of a master file are kept for backup purposes. If the latest version of the master file is damaged it can be recreated by re-running the previous update using the old master and transaction files.

The grandfather-father-son method of updating can be seen below.