Implementing Siebel Business Applications on DB2 UDB for z/OS > Migrating Data Using Siebel EIM > About Setting Up EIM for DB2 >

Considerations in Planning Data Mapping

Data mapping—an important part of preparing to run EIM—is particularly important on DB2 because of the way DB2 stores data in tables and indexes. When planning your data mapping, take into account such factors as partitioning, lookups during the load phase, and searches for online transactions.

About Importing Data to the Siebel Application for DB2

The Siebel Business Applications Data Model provides for many possible business needs and configurations. Many of the tables, columns, and indexes provided with Siebel Business Applications might not be relevant to your business. Because DB2 stores information in all columns, including NULL columns, consider carefully which data you should import into your Siebel application. Importing unnecessary data increases the size of tables and indexes, which can affect performance.

For information on dropping columns and indexes and reducing column sizes using Siebel Tools, see Customizing a Development Environment.

The MS_IDENT Column for DB2 for z/OS

The MS_IDENT column exists in every EIM table and is specific to DB2 for z/OS. It allows DB2 to automatically generate unique and sequential values for each row in a table.

This column is the unique identity column created using the Generated Always with Identity option.

CAUTION:  If you load data into this column using load utilities, your import might fail. Such failure can occur particularly when migrating data from a Siebel application on DB2 for UNIX or Windows to a Siebel application on DB2 for z/OS.

How to Presort Data During Initial Load

When loading the EIM tables with legacy data, sort this data on the partitioning key that is used on the target base table. When sorting string data, use the same character-collating sequence used in the target database. During this load, also preassign and load batch numbers corresponding to the partitioning scheme of the target base tables when possible. This method is particularly useful for those processes, such as Accounts or Contacts, where the partitioning key is based on business data rather than on a generated key. Preassigning and loading batch numbers generally improves EIM throughput, as the data is then loaded sequentially and by partition into the target base table.

TIP:   To further improve performance, after the EIM tables are loaded with partitioned data, unload this data in clustering order, and then reload it.

Implementing Siebel Business Applications on DB2 UDB for z/OS