Breast cancer may cause swollen axillary lymph nodes since the lymph vessels of the breast drain into the lymph nodes of the armpit. These nodes become enlarged when cancer cells spread beyond the breast tissue.
Relational database. (Redirected from Database constraints) A relational database is a digital database whose organization is based on the relational model of data, as proposed by E. F. Codd in 1970. The various software systems used to maintain relational databases are known as a relational database management system (RDBMS).
Constraint (mathematics) In mathematics, a constraint is a condition of an optimization problem that the solution must satisfy. There are several types of constraintsâprimarily equality constraints, inequality constraints, and integer constraints. The set of candidate solutions that satisfy all constraints is called the feasible set.