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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
Under privileges for named row 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.

Under privileges for named row types

For named row types, you can grant or revoke the Under privilege, which controls whether users can assign a named row type as the supertype of another named row type in an inheritance hierarchy. The Under privilege is granted to PUBLIC automatically when a named row type is created (except in ANSI-compliant databases). In an ANSI-compliant database, the Under privilege on a named row type is granted to the owner of the type.

To restrict certain users' ability to define a named row type as a supertype in an inheritance hierarchy, you must first revoke the Under privilege for PUBLIC and then specify the names of the users to whom you want to grant the Under privilege. For example, to specify that only a limited group of users can use the named row type person_t as a supertype in an inheritance hierarchy, you might execute the following statements:

REVOKE UNDER ON person_t
   FROM PUBLIC;

GRANT UNDER ON person_t
   TO howie, jhana, alison

For information about how to use the UNDER clause to create named row types in an inheritance hierarchy, see Type inheritance.