Progress
SQL-89
Guide and Reference
Choosing a Tool for Creating and Maintaining Database Tables
To define the structure of a database, you can use Progress/SQL Data Definition Language (DDL), the Progress Data Dictionary tool, or both. However, you must maintain each table the same way you define it. If you create a table with Progress/SQL DDL statements, you can use only Progress/SQL statements to change the privileges and structure of that table-you cannot use the Progress Data Dictionary. However, you can use the Data Dictionary to set or alter schema information that SQL DDL does not maintain, such as the Description and Help fields. Similarly, you must use the Data Dictionary to make changes to the structure of a table created with the Data Dictionary.
Progress Software Corporation recommends that you define tables by using the Progress Data Dictionary, even if you plan to access the tables through Progress/SQL. This establishes a consistent way of maintaining the schema. But if you plan to modify the schema dynamically—perhaps by running an application containing DDL—you must define the schema by using Progress/SQL, and sacrifice some features of the Progress Data Dictionary. For example, if you define tables using SQL, you cannot deny the blank user ID access to the tables, since you define access rights of the blank user ID using the Data Dictionary. For more information on the blank user ID, see the Progress Database Administration Guide and Reference and the Progress Client Deployment Guide.
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