cardinality的意思|示意

English word cardinality is a mathematical term to refer to the number of elements in a set or the size of a set. In computer science, cardinality can also be used to describe the size of a database table or relation. It is used to determine the number of different values or entities in a set.

The cardinality of a certain set can be determined by counting the number of elements in that set. For example, the cardinality of the set {a, b, c} would be 3 since there are three elements in the set.

In SQL databases, cardinality is used to determine the data type of each field and the number of entries in each table. This allows the database to search quickly and efficiently by optimizing the query. For example, cardinality can be used to reduce the number of records returned when searching a database.

Cardinality is also important in computer algorithms as it determines the complexity of the problem that needs to be solved. The cardinality of a set can be used to describe the size of the problem and its complexity. Generally, the more elements in a set, the harder the problem.

Overall, the English word cardinality is a mathematical term used for the size of a set and the number of elements in a set. It can be used in computer science to help optimize database queries and improve algorithm complexity.