An SGML document may have a structure such as chapter, section, item, and list in the document itself. If the individual items of data have structures, the user must enable the plug-in to recognize the each data item's structure when the document is registered. This type of information that is specific to a plug-in and that is to be used by the plug-in for data manipulation is called registry information. The facility by which HiRDB maintains registry information is called the registry facility.

Before the registry facility can be used for a plug-in, it must be initialized; HiRDB's registry facility initialization utility (pdreginit) is used for this purpose.

Initializing the registry facility creates a registry RDAREA and a registry LOB RDAREA and stores in HiRDB RDAREAs a table for managing registry information (registry management table) and data manipulation stored procedures (such as for registering information into the registry management table).

Table 10-2 shows the RDAREAs used for storing information related to the registry facility.

Table 10-2 RDAREAs for storing information related to registry facility

Registry facility information	Storage RDAREA
Registry management table	Registry RDAREA or registry LOB RDAREA*
Data manipulation stored procedures, such as for registering information into the registry management table	Data dictionary LOB RDAREA

^* The RDAREA to be used for storing information is determined automatically on the basis of the length of the data to be registered (up to 32,000 bytes is stored in the registry RDAREA; 32,000 bytes or longer is stored in the registry LOB RDAREA).

For details about registry facility initialization, see the HiRDB Version 8 Installation and Design Guide. For details about the registry facility setup utility (pdreginit), see the HiRDB Version 8 Command Reference.