Karteikarten
Database
Karten in diesem Stapel (11)
- 1What is a Database?A persistent organised store of data on a computer
- 2What is redundancy?‘Something’ or data that is unnecessary!
- 3What is a entity?An entity is a real-world object
- 4What is a relational database?A relational database has more than one table and the tables are linked using key fields.
- 5What is a flat-file database?Database contains a single table
- 6Advantages of a relational database? (0/6)Avoids data duplication
Avoids inconsistent records
Easier to change data
Easier to change data format
Data can be added and removed easily
Easier to maintain security - 7Advantages of using an electronic database? (0/8)Databases can store very large numbers of records efficiently (they take up little space).
It is very quick and easy to find information.
It is easy to add new data and to edit or delete old data.
Data can be searched easily, eg 'find all Ford cars'. (Queries)
Data can be sorted easily, for example into 'date first registered' order.
Data can be imported into other applications, for example a mail-merge letter to a customer saying that an MOT test is due.
More than one person can access the same database at the same time - multi-access.
Security may be better than in paper files. - 8What is a primary key?A primary key is a field in a table which is unique and enables you to identify every record in that table
- 9What is a foreign key?A foreign key is used to link tables together and create a relationship. It is a field in one table that is linked the the primary key in another table.
- 10Define RecordA record is all of the data or information about one person or one thing.
- 11Define a FieldA field is one piece of data or information about a person or thing.
Informationen
- Beschreibung
- GCSE Computer Science (Databases) Karteikarten am Database, erstellt von Lyssa Badger am 27/05/2015.
- Erstellt von
- Lyssa Badger
- Aufrufe
- 32
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