cardinality - Read For Learn

What is cardinality in Databases?

A source of confusion may be the use of the word in two different contexts – data modelling and database query optimization. In data modelling terms, cardinality is how one table relates to another. 1-1 (one row in table A relates to one row in tableB) 1-Many (one row in table A relates to many … Read more

What is the definition of cardinality in SQL

They are speaking the same thing and it has to do with tuples (relational algebra) or rows (layman’s term). When it says high-cardinality are possible values of particular attribute (or field) that are unique and therefore the number of rows or tuples are higher: Example: As far as as StudentID the cardinality is high because it is unique. In this it … Read more