Extending the basic structure of a database and modifying the structure

The basic structure of a SESAM/SQL database simply comprises the catalog space and, if logging is enabled, the CAT-REC file and the first CAT-LOG file. The basic structure can be extended as follows to create an operational SESAM/SQL database capable of accommodating user data:

• Creating system entries

• Granting special privileges

• Defining storage groups for user spaces

• Inserting the first media record for DA-LOG and PBI files or the HSMS work file in the media table

• Creating user spaces

• Creating schemas

The structure of an operational SESAM/SQL database can be modified by means of the following measures to adapt it to current requirements:

• Creating and deleting system entries

• Granting and revoking special privileges

• Defining, modifying, and deleting storage groups for user spaces

• Maintaining the media table (inserting or deleting media records, modifying descriptions of file attributes in the media table)

• Creating, modifying, and modifying user spaces

• Creating, modifying, and deleting schemas

• Modify properties of the database

The above measures are explained in detail in the sections that follow.

The table below provides an overview of the activities that need to be carried out, and links the tasks with the relevant SQL or utility statement. The right-most column indicates the main functions in the utility monitor that the database administrator uses to complete each task.

Activity	Statement and function	Main function in the utility monitor
Create and delete system entries	CREATE USER Assign authorization key (for SQL user) CREATE SYSTEM_USER Create a system entry DROP USER Delete an authorization key and the associated system entries DROP SYSTEM_USER Delete a system entry	Main function CREATE CATALOG (CRC) and continuation forms and Main function ALTER CATALOG (ALC) and continuation forms
Grant and revoke special privileges	GRANT Grant special privilege REVOKE Revoke special privilege
Create, modify and delete storage groups	CREATE STOGROUP Create a storage group ALTER STOGROUP Modify a storage group DROP STOGROUP Drop a storage group	Main function SSL and continuation forms
Add the first media record for DA-LOG and PBI files to the media table	CREATE MEDIA DESCRIPTION Add the first media record for the databasespecific DA-LOG and PBI files respectively to the media table.	Main function CREATE CATALOG (CRC) and continuation forms
Maintain the media table	ALTER MEDIA DESCRIPTION Add or delete media records; modify the description of file attributes DROP MEDIA DESCRIPTION Delete all the media records for a specific file type.	Main function ALTER CATALOG (ALC) and continuation forms
Create, modify and delete user spaces	CREATE SPACE Create user space ALTER SPACE Alter user space DROP SPACE Delete user space	Main function SSL and continuation forms
Create, modify and delete schemas	CREATE SCHEMA Create a schema Alter a schema DROP SCHEMA Delete a schema	Main function CREATE SCHEMA (CRS) and continuation forms Main function ALTER SCHEMA (ALS) and continuation forms
Modify properties of the database	ALTER CATALOG Modify properties	Main function ALTER CATALOG (ALC) and continuation forms

Table 67: SQL/utility statements and main utility monitor functions for extending and modifying the structure of a database