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Logical Components of a Dictionary

Dictionary Components

You can group the six areas of the dictionary into logical components based on the inherent relationships that exist between the dictionary areas:

Components of a System Dictionary

A system dictionary always contains all three components:

• A base definition component
• A catalog component
• A message component

Components of an Application Dictionary

An application dictionary may contain all or a subset of the components. At sites without the SQL option, an application dictionary usually contains only a base definition component and a shared message component.

Sharing the Message Area

In most cases, an application dictionary will not have its own message area. Since the runtime system uses only the system message area (SYSMSG.DDLDCMSG) to display messages, most application dictionaries will share the system message area, rather than having a separate message area.