Implementing Siebel eBusiness Applications on DB2 UDB for z/OS and OS/390 > Preparing for Implementation on the DB2 Host >
Estimating the Storage Space Required
The space needed by DB2 varies primarily based on the total number and types of users supported. Consult the IBM DB2 UDB for z/OS and OS/390 technical documentation for more information on these requirements. The space required for Siebel data and indexes varies depending on what Siebel functionality you implement and the amount and nature of data supporting it. The process for making accurate database size calculations is a complex one involving many variables. The following guidelines will assist you in the process:
 Determine the total number, and types, of users of Siebel eBusiness 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 per user (for example, 100 accounts per sales representative) and calculate an estimated total number of records per entity for your total user base.
 Calculate the average record size per 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 onehalf the storage required.
 Allow for a margin of error in your total size calculation.
 Factor growth rates into your total size calculation.
