What do you mean by relational algebra and relational calculus?

What is relational algebra and relational calculus?

Relational Algebra and Relational Calculus are the formal query languages for a relational model. Both form the base for the SQL language which is used in most of the relational DBMSs. Relational Algebra is a procedural language. On the other hands, Relational Calculus is a declarative language.

What do you mean by relational algebra?

Relational algebra is a procedural query language, which takes instances of relations as input and yields instances of relations as output. It uses operators to perform queries. An operator can be either unary or binary. They accept relations as their input and yield relations as their output.

Why is it called relational algebra?

The name comes from the mathematical notion of “relation.” It all started with E. F. Codd who in 1970 (in the article A Relational Model of Data for Large Shared Data Banks) proposed something now called relational algebra as the mathematical foundation of databases.

What is relational calculus used for?

The relational calculus consists of two calculi, the tuple relational calculus and the domain relational calculus, that are part of the relational model for databases and provide a declarative way to specify database queries.