In a database, cardinality refers to:
- How many unique values are in a column of a table
- How many rows a table contains
- How many columns a table contains
- Which command gets executed first
EXPLANATION
In the context
of databases, cardinality refers to the uniqueness of data values
contained in a column. High cardinality means that the column contains a
large percentage of totally unique values. Low cardinality means that
the column contains a lot of “repeats” in its data range.
It is not common, but cardinality also sometimes refers to the relationships between tables. Cardinality between tables can be one-to-one, many-to-one or many-to-many.
It is not common, but cardinality also sometimes refers to the relationships between tables. Cardinality between tables can be one-to-one, many-to-one or many-to-many.
0 comments:
Post a Comment