Database Server Directory Structure
The environment variable $INFORMIXDIR points to the directory where Informix is installed on your machine; normally this is set to /usr/INFORMIX. The standard Informix directory structure is built under INFORMIX directory by the Informix install process.
The standard Informix architecture uses the “Two-Task Model.” In this architecture, when a user connects to the database server a network thread is created to handle the network processing for that user.
Each Informix server instance consists of the following pieces:
At least eight database processes that operate the database.
At least three shared memory segments, through which the database processes communicate.
The $INFORMIXDIR/etc/sqlhosts file holds networking parameters for each accessible server instance.
Entries include server name, network protocol, host name and tcp-ip service.
The $INFORMIXDIR/etc/$ONCONFIG file.
This file primarily holds shared memory configuration parameters for the local server instance. These include the number of buffers, number of locks, size of the initial shared memory segment, and so on The “onconfig” file also includes pointers to the root dbspace, the temporary dbspace, and the physical log dbspace, as well as the names of the backup tape devices. By convention, these files are often given a name such as onconfig.inf11, where inf11 is the name of the server. This is helpful when managing multiple server instances on one host.
Hold the data stored in the database. Under UNIX, these may be either “raw” or “cooked” files. In either case they should be stored in a common directory, with links pointing to their physical locations, if necessary.
See the Administrator’s Guide for Informix Dynamic Server for more information.