IBM 5655-DB2, 5695-DF1 manual 1 DB2 Defined and Managed, User Defined and Managed

DB2 defined and managed spaces should be the choice by default. It is the easier of these solutions and is adequate for most table and index spaces in the majority of situations.

User defined table spaces provide more control of the data set placement and all VSAM definition options are available. Examples of where user defined table spaces may be required are:

•Table spaces that require specific DFSMS classes

•Table spaces with critical performance and availability requirements

•(In general, table spaces with special requirements)

3.3.1DB2 Defined and Managed

Figure 1 on page 14 shows an example of a DB2 defined table space. The CREATE TABLESPACE resolves the physical allocation and defines this table space to DB2. The STOGROUP DSN8G610 defines a set of volumes for the data set and PRIQTY specifies the size in KB. Indexes are created with a CREATE INDEX statement. The CREATE INDEX statement defines both the index and the associated index space. The CREATE INDEX also loads the index with entries that point to the data (index rows) unless the DEFER YES parameter is specified.

CREATE TABLESPACE PAOLOR11

IN DSN8D61A

USING STOGROUP DSN8G610

PRIQTY 20

SECQTY 20

ERASE NO

LOCKSIZE ANY LOCKMAX SYSTEM

BUFFERPOOL BP0

CLOSE NO

CCSID EBCDIC;

Figure 1. Creating a STOGROUP Defined Table Space

3.3.2 User Defined and Managed

Two steps are required to create user defined table spaces or index spaces.

1.The physical allocation is done with an IDCAMS DEFINE CLUSTER; this is shown in Figure 2 on page 14.

DEFINE CLUSTER -

( NAME(DB2V610Z.DSNDBC.DSN8D61A.PAOLOR1.I0001.A001) -

LINEAR - REUSE - VOLUMES(SBOX10) - RECORDS(4096 50) - SHAREOPTIONS(3 3) ) -

DATA -

( NAME(DB2V610Z.DSNDBD.DSN8D61A.PAOLOR1.I0001.A001) ) - CATALOG(DS2V6)

Figure 2. User Defined Table Space: Step 1—Define the Cluster

2.The table space or index space must be defined to DB2. An example is shown in Figure 3 on page 15. It must be noted that the high level qualifier, the

14Storage Management with DB2 for OS/390