IBM 5655-DB2, 5695-DF1 manual Table Space and Index Space Names for SMS, Let SMS Manage Everything

6.1.8 Table Space and Index Space Names for SMS

The recommendation in this book for finely tuned SMS installations is to imbed SMS codes into the names of DB2 table and index spaces. This is shown in Table 16 on page 56. The data set names have the structure shown in Table 3 on page 23, with a change in the space name itself. As explained in 6.1.7, “Assigning SMS Classes to DB2 Table Spaces and Index Spaces” on page 53, this name contains codes for the ACS routines. The ACS routines use these codes to establish Storage Classes, Management Classes and Storage Groups.

Table 16. Table Space and Index Space Names with SMS Codes

hlq.DSNDBx.dbname.uvssssss.ynnnn.Ammm

The elements of the space name are: uvssssss Space name:

uStorage Class code

vManagement Class code

ssssssUser assigned name

6.1.9 Managing Partitioned Table Spaces with SMS

With DB2, the user has choices on how to allocate and distribute the individual data sets of a partitioned table space. Two examples are shown in:

•Appendix A, Section A.2, “Partitioned Table Space, DB2 Defined, Without SMS” on page 162

•Appendix A, Section A.3, “Partitioned Table Space, User Defined, Without SMS” on page 164

SMS can also be used to distribute the individual partitions. Several different methods are possible; for example:

•Let SMS manage everything.

•Use one SMS Storage Group for each partition.

•Use one SMS Storage Group for one partitioned table space.

Let SMS Manage Everything

For many partitioned table spaces and index spaces, SMS can handle the partition distribution. If the number of volumes in the Storage Group is much larger than the number of partitions, then SMS will most likely place each partition on a separate volume.

Storage group SGDB20 is an example of this case. Table spaces and index spaces are allocated by SMS on these volumes, trying to balance the I/O activity on the volumes. This method should be adequate for many installations.This method is the preferred technique for storage administrators, because it has the advantage of simplicity.

This method can be used for table spaces and partitions, where each data set is a large fraction of a volume. Because a volume can only handle one partition, the separation is automatic. On the other hand, space fragmentation on the volumes

56Storage Management with DB2 for OS/390