4. Preparing for the Installation

This is the longest section and so it should be: after careful planning the installation itself should be an easy task.

4.1. Ingres Environment Variables

You will use Ingres environment variables to determine where to put further elements (besides the software itself) of the Ingres installation. These variables, unlike II_SYSTEM, are not shell variables but rather parameters of Ingres stored in a file. Some of them can be changed at any time after the installation, but altering the value of others requires a whole re-install. Later you will see which of them are of this "stable" nature.

During installation, you can choose between setting these variables manually or letting the installer set them to their default values (Express Install option).

In the following, we will take the relevant Ingres environment variables one by one and see what each of them is good for. It may help if you put their planned values on paper. You can find an Installation Worksheet in the Getting Started Guide which you can print out and use for this purpose.


Ingres uses an installation-wide transaction log file to record information on all changes made to any database. This information broadly consists of:

The transaction log resides in the II_LOG_FILE/ingres/log directory, where II_LOG_FILE is an Ingres environment variable. The name of the log file is ingres_log.

Express Install creates a log file of the minimum possible size, 16 Mb. Such a log file may not be large enough even in a development system. If you have free disk space and choose manual install (in which case you can specify the size of the log), set it to something much larger.

Both the location and the size of the log file can be changed at any time after installation. The method of doing this is described in the System Reference Guide.

You also have to decide if you want dual logging (mirroring the transaction log). If the log gets corrupted for any reason, Ingres stops and you have to recover your databases from backup. Therefore, in a live system, it is almost compulsory either to have some type of RAID protection of the log or to have it mirrored by Ingres. If you use dual logging, the copy of the log file can be found under II_DUAL_LOG/ingres/log. Its name is dual_log.

In a development or test environment, mirroring the log is not always necessary.

4.3. Database Locations

There can be any number of databases in an Ingres installation. A database, on the other hand, consists of files of different types. These are:

The files constituting a database reside in different directories, according to their types. These directories are specified indirectly, by means of Ingres locations.

There are five location types:

Let us see how these locations work in practice. Say we have a database, called test, with the following locations:

Every location of the test database points to the /opt directory. Elements of the database go in these directories:

Let us suppose now, that we extend the database to the following locations:

The database is effectively extended to the following directories:

DATALOC2 points to /opt, just like DATALOC1. Tables to be created in location DATALOC2 will go to /opt/ingres/data/default/test, the same directory where tables created in location DATALOC1 reside.

As is apparent from the example, we could have created just one location for DATALOC1, DATALOC2, CKPLOC, DMPLOC, JRNLLOC, and WORKLOC1.

Summarizing the main points about locations:

4.4. The iidbdb Database

Every Ingres installation has a master database called iidbdb. Ingres stores information about users, locations and user databases in this database. iidbdb is created by the installer.

You have to set the locations for iidbdb during installation. These locations are stored in the following Ingres environment variables:

These variables determine the default locations for every user database as well, if you do not override them when creating those databases. See Creating and Destroying Databases for more information.


Changing the value of II_DATABASE, II_CHECKPOINT, II_DUMP, II_JOURNAL, or II_WORK requires a complete re-install of Ingres.

Let us see these variables one by one.


II_DATABASE determines the data location of iidbdb. Its default value is $II_SYSTEM (in case of a manual install you can enter a different value for II_DATABASE, while Express Install inevitably sets it to $II_SYSTEM).

The size of iidbdb after the installation is somewhat more than 5 Mb. It can only grow significantly if you create hundreds of Ingres users, databases or locations.


II_CHECKPOINT contains the value for the checkpoint location of iidbdb. By default, it is also set to $II_SYSTEM.

The size of a checkpoint is just about the same as that of the database itself (at least until you modify the template file of the checkpoint program: it is possible, as you will see in Backup and Recovery). The installer takes the first checkpoint of iidbdb.

If you plan to place checkpoints of user databases under II_CHECKPOINT then you have to provide for more space here.

A further factor that must be taken into account is how long you want to keep backups. When starting the checkpoint program, you can request the deletion of older backups if you do not have too much free space.

4.7. II_DUMP

II_DUMP determines the dump location of the iidbdb database. By default, its value equals to that of II_CHECKPOINT.

By the end of the installation process, II_DUMP will contain a very small amount of data. If you always create checkpoints off-line then you will not need much space here.


II_JOURNAL contains the value for the journal location of the iidbdb database. Its default value is the same as II_CHECKPOINT's.

The first checkpoint, taken by the installer causes the first, small journal file to appear here. If you do not use different journal locations for user databases then the necessary amount of free space under II_JOURNAL depends on three factors:

4.9. II_WORK

II_WORK determines the work location of the iidbdb database. It also defaults to II_CHECKPOINT.

The problem of sizing the work location only arises if II_WORK serves as a work location for user databases as well. It is next to impossible to estimate the temporary disk space that will be needed here; however, having the size of the largest table multiplied by three should work as a starting point.

Remember that a database can have more than one work location. If the original location turns out too small, you can always extend the database to further work locations.

4.10. Other Ingres Environment Variables

Besides the Ingres environment variables that determine locations there are a couple more that you have to set during installation (or have Express Install set them to their default value). These are:

The (manual) installer prompts you for the value of two further parameters which are not Ingres environment variables:

After you have made up your mind on the values of all installation parameters, you know whether the default values for those variables that cannot be changed after installation are acceptable to you. If they are, you can choose Express Install.