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).
A constraint is anything that prevents the system from achieving its goal. There are many ways that constraints can show up, but a core principle within TOC is that there are not tens or hundreds of constraints. There is at least one but at most only a few in any given system.