As already outlined in Chapter 1, the data layer of the Siebel Repository consists of the following object types:
Table
Column
Index
User Key
It is important to understand that the information in the Siebel Repository metadata defines the physical schema in the relational database and not the other way round. A developer must, for example, define a new table in the Siebel Repository first using Siebel Tools and then use the Apply functionality to physically create the table in the database.
The Apply functionality and the ddlsync utility can be used to synchronize the logical schema (the data layer object definitions in the Siebel Repository) with the physical schema (the tables and indexes in the relational database).
Both the Apply functionality and the ddlsync utility will be discussed in detail later in this chapter.
In the following section, we will dive a little bit deeper into the data layer object types and their properties.