====== Primary key ======

The primary key in a DBMS is the field of a table that stores the values of an identifying [[english:glossary:attributes|attribute]]. These values are unique for different lines of the table. The primary key is the basis for the construction of an index that permits one to quickly find the information, and logically links with the spatial entities of the corresponding layer in the geographic database.

See also: [[english:glossary:identifier|Identifier]]