What is degree and cardinality in SQL?

Question

Could someone tell me what is degree and cardinality in SQL?

Answer 1

Degree in SQL refers to the number of attributes or columns in a table, while cardinality refers to the number of rows or tuples. Degree determines the horizontal size of a table, impacting storage and query performance. Cardinality affects the vertical size of a table, influencing storage requirements and query efficiency. These concepts are crucial in database design and optimization as they guide decisions related to indexing, storage allocation, and performance tuning to ensure efficient database operations.

Answer 2

Degree in SQL could be defined as the total number of entities that are involved in the relationship and it is usually 2 (binary relationship), and there is a possibility of Unary, and higher degree relationships can exist.

Whereas, Cardinality in SQL, could be defined as the number of entities that are involved in a relationship. Basically, there are 3 types of Cardinality for binary relationships; one-to-one (1:1), one-to-many (1:n), and many-to-many (n:x).

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Answer 3

Degree in SQL refers to the number of attributes or columns in a relation or table. It represents the horizontal size of the table. For example, if a table has three attributes, it has a degree of three.

Cardinality in SQL refers to the number of tuples or rows in a relation or table. It represents the vertical size of the table. For example, if a table has five rows, it has a cardinality of five.

Degree and cardinality are important concepts in database design and optimization. The degree of a table determines the number of attributes that need to be defined and stored for each row, impacting the storage requirements and query performance. Higher degrees can result in wider tables and potentially slower query execution. Cardinality, on the other hand, affects the size of the table and the efficiency of query processing. Tables with high cardinality may require more resources for storage and retrieval.

Understanding the degree and cardinality of tables helps database administrators and developers in designing efficient database schemas, indexing strategies, and query optimization techniques. It enables them to make informed decisions regarding storage allocation, indexing, and performance tuning to ensure optimal database performance.

Answer 4

Degree: number of attributes or columns in a table.

Cardinality: number of rows or tuples in a table.