Table spaces reside in database partition groups if they were created. Table 

space definitions and attributes are maintained in the database system 

catalog. Containers are assigned to table spaces. A container is an allocation 

of physical storage (such as a file or a device). 

A table space can be either system managed space (SMS), or database 

managed space (DMS). For an SMS table space, each container is a 

directory in the file system of the operating system, and the operating 

system s file manager controls the storage space. For a DMS table space, 

each container is either a fixed size pre allocated file, or a physical device 

such as a disk, and the database manager controls the storage space.

Schemas

A schema is an identifier, by default the user ID, which qualifies tables and 

other database objects. A schema can be owned by an individual, and the 

owner can control access to the data and the objects within it. A schema 

name is used as the first part of a two part object name. For example, a 

schema named Smith might qualify a table named 

SMITH.PAYROLL

.

Tables

A relational database presents data as a collection of tables. Data in a table 

are arranged in columns and rows. The data in the table is logically related, 

and relationships can be defined between tables. Table data is accessed 

through Structured Query Language (SQL), a standardized language for 

defining and manipulating data in a relational database. A query is used in 

applications or by users to retrieve data from a database. The query uses 

SQL to create a statement in the form of:

SELECT  FROM 

Views

A view provides a different way of looking at data in one or more tables; it is a 

named specification of a result table. The specification is a SELECT 

statement that runs whenever the view is referenced in a SQL statement. A 

view has columns and rows just like a base table. All views can be used just 

like base tables for data retrieval. Figure 1 7 shows the relationship between 

tables and views.

14 

MySQL to DB2 UDB Conversion Guide