4 Database structure In this chapter, we describe the IBM Content Manager OnDemand (Content Manager  OnDemand) database structure and relationships between the tables. We list the system  control tables and the important data table structures. We explain the relationship between  the tables when you load data, show how a search is performed on the database tables,  describe the system log, and describe special considerations for DB2 on z/OS. In this chapter, we cover the following topics: GLYPH<SM590000> System control tables GLYPH<SM590000> Main data table structures GLYPH<SM590000> Relationship between tables when data is loaded GLYPH<SM590000> Search sequence GLYPH<SM590000> System log GLYPH<SM590000> Database creation and relationships on z/OS ' Copyright IBM Corp. 2003, 2015. All rights reserved. 77