Joe Celko's SQL for Smarties, 3rd Edition

1.4. Other Schema Objects

Let’s be picky about definitions. A database is the data that sits under the control of the database management system (DBMS). The DBMS has the schema, rules and operators that apply to the database. The schema contains the definitions of the objects in the database. But we always say “the database,” as if it had no parts to it.

In the original SQL-89 language, the only data structure the user could access via SQL was the table, which could be permanent (base tables) or virtual (views). Standard SQL also allows the DBA to define other schema objects, but most of these new features are not yet available in SQL products, or the versions of them that are available are proprietary. Let’s take a quick look at these new features, ...