A car's ignition switch serves several purposes. First, it allows you to control the power to many of the car's accessories, preventing accessories from running down the car's battery when the car is parked for a long period of time.
Cardinality is the term used in database relations to denote the occurrences of data on either side of the relation. In the common data architecture, cardinality is documented with data integrity but not with data structure. There are several types of cardinality defining relationships between occurrences of entities on two sides of the line of relationships.
Sparsity and Density. In a database, sparsity and density describe the number of cells in a table that are empty (sparsity) and that contain information (density), though sparse cells are not always technically emptyâthey often contain a â0â digit. Tables and databases are the sum total of their sparse and dense cells.