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Database Sizing Guidelines


One of the most important factors to determine about the database is its overall size. During the planning phase, you need to allocate space for system storage, rollback segments and containers, temporary storage space, log files, and other system files required by the relational database management system (RDBMS), as well as space for the Siebel application data and indexes. If you allocate too little space for the system, performance will be affected and, in extreme cases, the system itself may be halted. If you allocate too much space, it may cause inefficiency.

The space needed by the database depends on the total number and types of supported users. It is recommended that you consult your vendor RDBMS technical documentation for more information on these requirements.

The space required for Siebel data and indexes depends on the functionality being implemented and the amount and nature of data supporting this functionality.

The process for making accurate database size calculations is a complex one involving many variables. Use the following guidelines:

  • Determine the total number, and types, of users of Siebel Business Applications (for example, 500 sales representatives and 75 sales managers).
  • Determine the functionality that you will implement and the entities required to support them. Typically, the largest entities are as follows:
    • 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 the total user base.
  • Using standard sizing procedures for the specific database, and Siebel Data Model Reference, calculate the average record size per entity and multiply by the total number of records. Typically, these entities span multiple physical tables, all of which must be included in the row size calculation. This determines the estimated data sizes for the largest entities.
  • You must add additional space for the storage of other Siebel application data. A rough guideline for this additional amount would be one-half the storage required for these key entities.
  • Indexes typically require approximately the same amount of space as data.
  • Be sure to allow for a margin of error in the total size calculation.
  • Be sure to factor growth rates into the total size calculation.
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