Characteristics of a relational database management system

We now write the rules that make a database management system relational.

Before putting the rules, we remember what a database management system was:

A database management system is defined as the set of programs that administer and manage the information contained in a database.

12 rules are established by which the database is relational:

Information Rule: All information is logically represented in tables.
Consistent handling of null values: Should support null values automatically regardless of data type.
Guaranteed access rule: Each data must be accessible through the combination of the table name, the column that contains it, and the primary key of the row.
Full sublanguage rule: Must allow a language whose syntax is well defined for database manipulation.
On-line catalog: A user must be able to access said catalog with his username and password.
High-level insertion, modification and deletion: It must be possible to perform such operations without altering the other data.
View update: It must be possible to update the views by the managing system.
Physical independence of the data: the way of storing the data does not influence its handling.
Logical data independence: changes to database objects do not have to affect users and programs.
Distribution independence: programs do not have to be altered by redistributing data.
Integrity independence: Integrity constraints are stored and created in the managing system and not in programs.
No subversion rule: If a database management system has a low-level language, this language cannot be used to destroy or circumvent the integrity rules or constraints expressed in the high-level relational language.