Implementing Siebel Business Applications on DB2 UDB for z/OS > Preparing for Implementation on the DB2 Host >

Estimating the Storage Space Required

The space needed by DB2 varies, depending on the total number and types of users supported. Consult the IBM DB2 for z/OS technical documentation for more information on these requirements.

The minimum DB2 storage space required for a typical Siebel 8.0 installation on DB2 for z/OS (installation of repository tables and seed data but with no user data loaded into the base tables) is between 5 GB and 20 GB, depending on the DEFINE parameter setting specified when the database objects were created.

If database objects are created with the DEFINE parameter set to YES, a DB2 catalog entry is created for the object and a data set is allocated for the object. If database objects are created with the DEFINE parameter set to NO, only a DB2 catalog entry is created for the object, so less space is required. Siebel Business Applications ship all table space and index schema definitions with the DEFINE NO option as the default. Therefore, no physical data sets are created until data is actually inserted into the table space.

NOTE:  DEFINE NO is only applicable to DB2-managed (STOGROUP) data sets and is ignored for user-managed (VCAT) data sets and for LOB table spaces.

The minimum space you require varies depending on the Siebel functionality you implement and the amount and nature of data supporting it. The process for making accurate database size calculations is complex, involving many variables. Use the following guidelines to assist you:

• Determine the total number and types of users of Siebel Business Applications (for example, 500 sales representatives and 75 sales managers).
• Determine the Siebel functionality that you will implement and the entities required to support them. Typically, the largest entities are:
  • Accounts
  • Activities
  • Contacts
  • Forecasts
  • Opportunities
  • Service Requests
• Estimate the average number of entities for each user (for example, 100 accounts for each sales representative) and calculate an estimated total number of records for each entity for your total user base.
• Calculate the average record size for each entity and multiply by the total number of records using standard sizing procedures for your specific database and the Siebel Schema definition. Typically, these entities span multiple physical tables, all of which must be included in the row size calculation. This calculation determines the estimated data sizes for the largest entities.
• Add extra space for the storage of other Siebel data. A rough guideline for this amount is one-half the storage required.
• Allow for a margin of error in your total size calculation.
• Factor growth rates into your total size calculation.
• A Siebel database that uses a Unicode encoding format will generally require more space than one that uses an ASCII or EBCDIC encoding format. For further information on the space requirements for Siebel Unicode databases, see About Migrating to a Siebel Unicode Database.

NOTE:  If you carry out a repository import and it fails, additional storage space is also required.