Relation scheme

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A relation scheme describes a set of attributes. If there are attributes, then there is a relation scheme. ${\displaystyle A_{1},\dots ,A_{n}}$ ${\displaystyle R=(A_{1},\dots ,A_{n})}$

A relation is a relation with the relation schema , i. H. ${\displaystyle r(R)}$ ${\displaystyle R}$

${\displaystyle r(R)=r(A_{1},\dots ,A_{n})}$contains tuples (lines) that correspond to the relation scheme. ${\displaystyle R}$

example

Imagine z. B. before a customer database in which customer data is stored in a table. The relation scheme for this customer relation could e.g. B. have the following form:

${\displaystyle Kundenschema=(Kundennr,Name,Telefon)}$

The relation with relation scheme , that is , could then contain tuples of the form . ${\displaystyle Kunde}$ ${\displaystyle Kundenschema}$ ${\displaystyle Kunde(Kundenschema)=Kunde(Kundennr,Name,Telefon)}$ ${\displaystyle (1234,Mustermann,10011112)}$

See also

• Relational database
• Scheme (computer science)