Implementing Siebel eBusiness Applications on DB2 UDB for z/OS and OS/390 > Customizing a Development Environment > Siebel Tools Considerations on DB2 UDB for z/OS and OS/390 >

Using Character Large Objects (CLOBs)

Siebel objects defined as LONGVARCHARs can also be stored as character large objects (CLOBs) on DB2 UDB for z/OS and OS/390. Siebel eBusiness Applications support CLOBs that allow up to 32 KB of data for a single data element in a table row.

The default setting for these objects in the Siebel Schema is LONGVARCHAR, because of the performance and storage characteristics of CLOBs in a DB2 UDB for z/OS and OS/390 environment. However, as an exception to this rule, customers running Siebel Marketing should change the LONG VARCHAR column in the S_NOTE table to a CLOB.

The Siebel installation, upgrade, and migration processes create all auxiliary objects necessary to support CLOBs, so that their use is transparent to the user. For more information on the use of CLOBs, see Upgrade Guide for DB2 UDB for z/OS and OS/390 for your operating system.

NOTE:  CLOBs are turned off by default. They must be turned on for each table by setting Clobs = Yes in the storage control file.

If CLOBs are chosen for a table, the Siebel installation, upgrade, and migration processes create all auxiliary objects necessary to support CLOBs, so their use is transparent to the user.

NOTE:  If you write your own scripts, it is recommended that you convert columns that contain scripts from LONGVARCHAR to CLOB to safeguard against space limitations that are inherent to the structure of z/OS and OS/390.

For more information on the use of LONGVARCHARs and CLOBs, refer to the Upgrade Guide for DB2 UDB for z/OS and OS/390 for your operating system.