Describe the Tables that are part of the Data Dictionary
Data Dictionary Tables
The data dictionary will contain several tables listing the tables, columns, indexes, and permissions comprising the database. The following two MouseOvers show the first few rows of two tables in a data dictionary. The first, SYSCATALOG, lists the tables in the database.
View the diagram below to learn more about SYSCOLUMNS characteristics.
The second, SYSCOLUMNS, lists the characteristics of every table column in the database.
The next lesson wraps up this module.
Metadata about the actual data structures themselves should be able to be selected from system tables, usually called system catalogs. For example, in Oracle these tables make up the Oracle Data Dictionary. These catalogs or library tables contain the key pieces of data about the Physical model in data element form. Some even store the definitions of the tables and columns. This emphasizes that the data model and database structures are available for public use.
data dictionary: A list of descriptions of data items to help developers stay on the same track.