To load an IMS database

From within the IDE

In COBOL Explorer, right-click a .dbd file in your project, and click Database Utilities > Load.
In the Load IMS database dialog, specify the .dat file to use in the Input/Output file name field.
Set the correct File layout and any other settings as required, and click OK.

From an Enterprise Developer command prompt

Navigate to the folder containing the .dat files.
Enter the following command for each .dat file:
```
mfims imsdbu load datfilename
```

Note: datfilename is case sensitive.

By default, this loads the database from a file with the same basename as datfilename but with the extension .DBU. You can change this behavior using the DSN and LAYOUT options.

From JCL

Execute the MFDBUJCL utility:

//step EXEC PGM=MFDBUJCL,PARM='LOAD,database,dataset'
//SYSOUT DD SYSOUT=*

Where database is the name of the database and dataset is the data set where the database is located. For more information about the MFDBUJCL program, see IMSDBUJCL Utility.