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

Creating Custom Extensions to the Siebel Schema

There are several different scenarios for Siebel schema extensions:

• Creating a small extension column, so the table fits into its existing table space
• Creating a large extension column, so the table has to be redefined to a larger page size and therefore a larger table space
• Creating an extension table

CAUTION:  If a LONGVARCHAR column is defined for a table, attempting to add an extension column to the table causes an error. This is because a LONGVARCHAR column uses all the space in a table space that is not used by the non-LONGVARCHAR columns, leaving no space available for an extension column. In this case, use an extension table instead. For further information, see LONG Columns on DB2 UDB for z/OS and OS/390 and Other DBMS Platforms.

The process of creating a small extension column is the same on the z/Series as on other platforms and is documented in Using Siebel Tools.

To create a large extension column or an extension table, you must specify a 16-KB or 32-KB table space:

• If developing on DB2 UDB for Windows or UNIX, you must enter a 16-KB or 32-KB table space in the Apply Schema screen. (See Step 4.)
• If developing on DB2 UDB for z/OS and OS/390, your DBA must edit the storage control file to specify in which database and table spaces the new extension column or table should reside.

NOTE:  Creating tables with Identity type columns or extension columns of Identity type is not supported

For information on estimating storage needs, see Preparing for Implementation on the DB2 Host.