DB+-+Flat-file+Databases

__Flat File Databases__ **By Blair**

In a flat file database, the data is stored in a single table. They are not connected in any way, unlike a Relational Database. There are a number of problems with this type of database which include:

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 * Data is very likely to be **__duplicated__**__.__ This is because a new record must be created for new data, which means that some of the same data would have to be copied into this new record.
 * The duplication of data can then lead to the possibility of **__data inconsistency__**. This is when data that are on two or more different records are supposed to be exactly the same but are different. This is due to human error, the data is misspelled as it has to be typed in manually and is not automatic. As a result of this it could be very difficult or almost impossible to be certain which record contains the correct data.
 * Removing data could lead to other data being completely deleted from a record. This is called **__deletion anomaly__**. An example of this would be a database of DVD rentals; if a customer had only rented one DVD and then the DVD was removed from the database, the customer would also be deleted.
 * Certain data must be entered for other data to be entered. This is called **__insertion anomaly__**. An example of this would be a database of DVD rentals; to store information about a customer, details of DVDs they have rented must also be entered.