Schema definitions describe the data, and especially the object classes and attribute types that can be stored in the directory. By default OpenDJ conforms strictly to LDAPv3 standards pertaining to schema definitions and attribute syntax checking, ensuring that data stored is valid and properly formed. Unless your data use only standard schema present in OpenDJ when you install, then you must add additional schema definitions to account the data your applications stored.

Out of the box, OpenDJ comes with many standard schema definitions. In addition you can update and extend schema definitions while OpenDJ is online. As a result you can add new applications requiring additional data without stopping your directory service.

This chapter demonstrates how to change and to extend OpenDJ schema. This chapter also identifies the standard schema definitions available when you install OpenDJ.