Home
Designing databases
The first step in creating a relational database is to construct a data model, which is a precise, complete definition of the data you want to store. After you prepare your data model, you must implement it as a database and tables. To implement your data model, you first select a data type for each column and then you create a database and tables and populate the tables with data. You can also implement fragmentation strategies and control access to your data.
Designing and Implementing a Database
The Informix® Database Design and Implementation Guide provides information to help you design, implement, and manage your Informix databases. It includes data models that illustrate different approaches to database design and shows you how to use structured query language (SQL) to implement and manage your databases.
Managing databases
Grant and limit access to your database
Grant privileges
Type-level privileges
Usage privileges for user-defined types

Designing databases
The first step in creating a relational database is to construct a data model, which is a precise, complete definition of the data you want to store. After you prepare your data model, you must implement it as a database and tables. To implement your data model, you first select a data type for each column and then you create a database and tables and populate the tables with data. You can also implement fragmentation strategies and control access to your data.
- Designing and Implementing a Database
  The Informix® Database Design and Implementation Guide provides information to help you design, implement, and manage your Informix databases. It includes data models that illustrate different approaches to database design and shows you how to use structured query language (SQL) to implement and manage your databases.

Usage privileges for user-defined types

To control who can use an opaque type, distinct type, or named row type, specify the Usage privilege on the data type. The Usage privilege allows the DBA or owner of the type to restrict a user's ability to assign a data type to a column, program variable (or table or view for a named row type), or assign a cast to the data type. The Usage privilege is granted to PUBLIC automatically when a data type is created (except in ANSI-compliant databases). In an ANSI-compliant database, the Usage privilege on a data type is granted to the owner of the data type.

To limit who can use an opaque, distinct, or named row type, you must first revoke the Usage privilege for PUBLIC and then specify the names of the users to whom you want to grant the Usage privilege. For example, to limit the use of a data type named circle to a group of users, you might execute the following statements:

REVOKE USAGE ON circle
   FROM PUBLIC;

GRANT USAGE ON circle
   TO dawns, stevep, terryk, camber;