Implementing Siebel Business Applications on DB2 for z/OS > Customizing a Development Environment >

About Siebel Tables and CLOB Columns

This topic describes how character large object (CLOB) data types are implemented on the z/OS platform.

When you install Siebel Business Applications, a number of Siebel application objects are defined as CLOB data types in the Siebel Repository; such objects can have up to 128 KB of data for a single data element in a table row. Other Siebel tables have columns that are defined as LONG columns in the Siebel Schema, and as LONG VARCHARs in the Siebel Repository, but are converted to CLOB columns on z/OS. Siebel objects that are defined as LONG columns but stored as CLOBs can have up to 16,350 bytes of data for a single data element in a table row.

Siebel Tables with LONG Columns That Are Created as CLOBs

The following Siebel tables have columns defined as LONG that are converted to CLOB columns on z/OS (Clobs is set to Yes in the storage control file definition of the table). Siebel Business Applications use CLOB columns for these tables to avoid the in-memory sort limit of DB2 for z/OS.

These tables belong to the Siebel Repository and are not read or updated frequently so the performance issues associated with using CLOB columns, described in Issues in Using CLOB Columns Instead of LONG VARCHAR Columns, are not relevant:

• S_BITMAP_DATA
• S_DMND_CRTN_PRG
• S_EVT_MAIL
• S_NOTE
• S_NOTE_ACCNT
• S_NOTE_CON
• S_NOTE_OPTY
• S_SCHMST_DBSCPT
• S_SCHMSTEP_SCPT
• S_SERVICE_SCRPT

If appropriate for your environment, you can enable CLOB columns for Siebel tables other than those listed. For information on this task, see Converting LONG VARCHAR Columns to CLOB Columns.

Siebel Tables Defined with CLOB Columns

The following Siebel tables have columns that are defined as CLOB columns in the Siebel Repository. Activity on these tables is quite high, but these tables cannot be stored in 32-KB table spaces because they have very large columns (greater than 128 KB) and so could encounter the in-memory sort limit of DB2 for z/OS:

• EIM_AUDIT_ITEM
• EIM_AUDIT_READ
• S_AUDIT_ITEM
• S_AUDIT_READ
• S_BR_GBL_BINARY
• S_BR_MODULE_BIN
• S_DOCK_TXN_LOG
• S_TU_LOG
• S_TU_LOG_X_01
• S_TU_LOG_X_02
• S_TU_LOG_X_03
• S_TU_LOG_X_04
• S_TU_LOG_X_05
• S_WEBCHNL_SES
• S_WEBCHNL_SNSVC

If appropriate for your environment, you can also define new extension columns for tables as CLOB data types. For information on this task, see About Defining New Extension Columns as CLOB Data Types.