An artificial or alias or surrogate key is created by the database designer/developer if there is no candidate key, i.e. no logical, simple field to be the primary key. An artificial key is a short ID number used to uniquely identify a record.
Such an internal primary key ID is recommended for all tables. They should always be invisible to the user, to prevent any potential external influence regarding their appearance and composition.
It is always wise to keep the primary key as short as possible to minimize the amount of disk space required, and to improve performance; therefore artificial keys should also be as short as possible. An ideal solution for the generation of an artificial key is the use of an autoincrement generator ID number.
IBExpert recommends this solution be used as an internal primary key for all tables.
Usually such an artificial/alias/surrogate key is just an autoincrement integer field so that each record has it's own unique integer identifier. For example:
CREATE TABLE CUSTOMERS ( CUSTOMER_ID INTEGER NOT NULL, FIRST_NAME VARCHAR(20), MIDDLE.NAME VARCHAR(20), LAST_NAME VARCHAR(20); ...);
In this case CUSTOMER_ID the artificial or surrogate key.