Working With Database Objects

A database object specifies the database name, database type, file locations, and other attributes. You can perform the following basic operations on database objects:

• Create and alter database objects

  Note: You can create as many databases as your operating system allows.

• View existing database objects, including the detailed properties of each individual object
• Drop database objects

In VDBA, use the Databases branch in the Database Object Manager window.

You can also accomplish these tasks using the createdb, catalogdb, relocatedb, infodb, and destroydb system commands. For more information, see the Command Reference Guide.

Createdb Privilege

The createdb privilege is required to create a database. For example, this privilege is required to use the createdb system command or to use the equivalent operation in VDBA. This subject privilege is granted by default to the system administrator, who in turn can grant it to other users, such as database administrators.

How a Database Is Created

When you create a database the following occurs:

• The system catalogs in the master database (iidbdb) are updated.
• A new subdirectory is created, with the name of the database, under the database location for the database. Later, similar subdirectories are created under the work, journal, dump, and checkpoint locations for the database, as needed.
• The configuration file (aaaaaaaa.cnf) and the core system catalogs (aaaaaaax.t00, x=b through e) are copied to the new database directory.
• The DBMS system catalogs for the new database are created and modified.
• The standard catalog interface is created.
• The user interface system catalogs (restricted by any -f flag options) are created.
• If creating a distributed database, Ingres Star system catalogs for the database are initialized and modified.
• Select permission for the system catalogs is granted to public.

Extend and Unextend a Database

You can extend a database to use additional data and work locations. Locations must exist prior to this operation and must be specified with a Usage Type of database or work.

To extend a database, use either the Alter Database dialog in VDBA or the extenddb command.

After extending to another data location, create new tables and indexes in the extended location, and modify existing tables and indexes to use the extended location. For details on creating and moving tables, see the chapter "Managing Tables and Views."

When you extend to a new work location, the system spreads the workload between the initial location (specified at create time) and the extensions.

Unextending a database reverses the extend operation and deletes the entry from the configuration files so the location can be used again.

Note: After unextending a database location, you should checkpoint the database. Previous checkpoints cannot be used because they reference a location that is no longer accessible to the database.

To unextend a database, use either the Alter Database dialog in VDBA or the unextenddb command. For additional information, see the Command Reference Guide and online help.

Relocate Database Files

You can relocate journal, checkpoint, and dump work files for an existing database. Locations must exist prior to this operation and must be specified with an appropriate Usage Type (that is, journal, checkpoint, or dump, depending on the type of file you want to relocate). When you relocate checkpoint, journal, or dump files, the existing files are moved to the new location and any new files are created there.

To relocate database files, use the Alter Database dialog in VDBA. For more information, see the online help topic Altering a Database.

You can also accomplish this task using the relocatedb system command. For more information, see the Command Reference Guide.

How a Database Is Dropped

When you drop a database, the following occurs:

• The database, checkpoint, journal, dump, and work directories for the database are deleted.
• All traces of the database are removed from the master database (iidbdb).
• The Application-By-Forms object file directories for any applications associated with the database (but not the source code directories) are deleted.

Caution! Do not set ING_ABFDIR to be your default login directory or other directory that contains your own files. Your files can be inadvertently destroyed if a destroydb dbname command is issued and dbname is the same name as the ING_ABFDIR directory.