SQL/MX Release 2.0 Best Practices

Database Sizing Considerations 18

Database Sizing Considerations

General Rules for Sizing

This section includes some general rules for sizing a database system when very few details are known

about the application.

• A processor supports about 30 to 50 gigabytes of data (logical data, based on common customer

implementations); the number varies based on the processors and types of storage chosen. Please

consult your hardware representative for your processor and storage configuration abilities.

• The total table space is about 1.5 times that of the base table data. Indexes generally are used only

on the dimension tables.

• Specify at least one empty disk volume for sort and workspace.

• Specify at least one empty disk volume for OSS for standard I/O.

• Purchase the maximum memory that the processors can support.

• Plan to mirror all volumes. There is an advantage to parallel reads from a disk that is mirrored.

Sizing Questionnaire

These questions arise from the need to properly size the NonStop system. Much of the information needed

probably already exists from the initial project-planning activities.

Quantifiable Metrics

For each legacy system involved:

• How many records will be extracted:

• For the initial load?

• For cyclical updates?

• What are the record sizes?

• What is the frequency of extraction?

For the Database System

• What is the required transaction each second?

• What are the service-level agreements?

• How many rows will be loaded initially?

• What is the anticipated row size?

• What is the frequency of updates:

• For the operational data store (ODS)?

• For the warehouse?

• How many rows will be inserted cyclically? Updated? Deleted?

• What are the response-time requirements?

• What is the number of concurrent users? (For sizing, concurrent is defined as the number of users

actively running a query and not the number of sessions established.)

• What is the total number of users?

• What is the total number of sessions?

• How long will a history be maintained:

• In the ODS?

• In the warehouse?