Databases

In DB2, a database is a set of DB2 objects. When a DB2 database is defined, a name is given to an eventual collection of tables and associated indexes, as well as to the table and indexspaces in which those tables and indexes reside. A single database, for example, can contain all the data associated with one application or with a group of related applications. Collecting that data into one database lets you start or stop access to all the data in one operation, and grant authorization to access all the data in a single unit.
carcudb2
In DB2, a database is a set of DB2 objects. When a DB2 database is defined, a name is given to an eventual collection of tables and associated indexes, as well as to the table and indexspaces in which those tables and indexes reside. A single database, for example, can contain all the data associated with one application or with a group of related applications. Collecting that data into one database lets you start or stop access to all the data in one operation, and grant authorization to access all the data in a single unit.
Shared Read-Only Data (ROSHARE)
Shared read-only data allows multiple DB2 subsystems to share the same DASD copy of a database. This is accomplished by creating a database on the owning subsystem and specifying ROSHARE OWNER in the CREATE DATABASE syntax. That database and all of its dependent objects must then be created on the other DB2 subsystems from which you want to read the data. These databases are identified as shared read-only databases.
When tables are created on the reading subsystems, they must specify the OBID (object ID) of the corresponding table on the owning subsystem database. DB2 uses the OBID attribute to identify which VSAM data sets should be accessed and read. Data sets are created only on the owning system, and they are shared by all shared read-only databases on other systems. You can specify the ROSHARE option for each database and the OBID for each table using the Table Database Create screen. The proper SQL statements will be generated.