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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
Distributed queries
Configure the database server to use distributed queries

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.
  - Basics of database design and implementation
  - Managing databases
    - Table fragmentation strategies
    - Grant and limit access to your database
    - Distributed queries
      - Overview of distributed queries
      - Configure the database server to use distributed queries
      - Syntax of a distributed query
      - Monitor distributed queries
        Use the onstat -x command to display transaction information originating on the coordinator of a distributed query.
      - Server environment and distributed queries
        Set the DEADLOCK_TIMEOUT configuration parameter and the PDQPRIORITY environment variable to specify information for distributed queries.
      - Logging-type restrictions on distributed queries
      - Transaction processing
        When using distributed queries in a transaction processing environment, be aware of the effect of the isolation level of a transaction, the effect of the SET LOCK MODE statement in conjunction with the DEADLOCK_TIMEOUT configuration parameter, and the two-phase commit protocol.
  - Object-relational databases

Configure the database server to use distributed queries

To use multiple Informix® servers for distributed queries, you must make sure that all of the database servers involved are configured to enable server-to-server communications over the network.

Edit the following configuration files to allow distributed queries:

The sqlhosts file to hold connectivity information about other servers
The onconfig file to set DBSERVERALIASES, NETTYPE, REMOTE_USERS_CFG, and REMOTE_SERVER_CFG configuration parameters
The file specified by the REMOTE_USERS_CFG or REMOTE_SERVER_CFG configuration parameter to configure network security
The /etc/services and /etc/hosts files, or their equivalents managed via network systems such as NIS+, for TCP/IP network configuration

Note: To configure network security, use the file you specify with the REMOTE_USERS_CFG or REMOTE_SERVER_CFG configuration parameter instead of the hosts.equiv or trusted users' rhosts files.

To set up several database servers to use distributed queries, use one of the following ways to store the sqlhosts information for all the databases:

In one sqlhosts file, pointed to by the INFORMIXSQLHOSTS environment variable
In separate sqlhosts files in each database server directory
In a centrally managed file on a network mounted, read-only file system, with the sqlhosts file in each database server directory being a symbolic link to the centrally managed file

Note: To use non-root installations of the database server for distributed queries, you must set one of the following configuration parameters in the onconfig file:

REMOTE_USERS_CFG, which specifies the alternative to using the rhosts file for listing trusted users on a remote server.
REMOTE_SERVER_CFG, which specifies the alternative to using the etc/hosts.equiv file for listing trusted remote hosts.