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About Siebel Additive Schema Changes Mode

Environments: Production test, production.

As of Siebel CRM 8.0, Apply Additive Schema Changes mode is part of the Database Server Configuration Utilities. The purpose of Additive Schema Changes is to reduce the downtime required for the production database upgrade.

Additive Schema Changes generates an SQL script. You run the script on the live production database before you take it offline to perform the production upgrep. The script performs certain upgrade steps that are normally part of the production upgrep. This reduces the number of steps the upgrep must perform while the database is offline, and thus reduces database downtime.

Running the SQL script is optional. If you do not run it, then the regular production upgrep performs the steps in the SQL script.

Types of Changes

Additive Schema Changes make the following types of schema changes to support the new release. These changes do not adversely affect data integrity or database normalization:

• Creating new tables.
• Adding columns to an existing table. The column must either be specified as null, or if the column is not null, it must have a specified default value.
• Creating non-unique indexes on new tables.
• Increasing column sizes for numeric or varchar columns. The column must not be the basis for a picklist. Also, the resultant cumulative row size must not be larger than the data page size.
• Revising a not-null column to null.
• Revising data type from char to varchar.

Implementation of Additive Schema Changes

You generate the Additive Schema Changes script by starting the Database Server Configuration Utilities and choosing Apply Additive Schema Changes. A wizard prompts you for environment information similar to other upgrade modes.

After you review and confirm your entries, the wizard populates the platform\driver_additive_gen.ucf file, where platform is the database type (DB2, MSSQL, Oracle).

The Upgrade Wizard, then performs the following steps:

• Reads the master_additive_gen.ucf file to obtain environment information and the name of the driver file.
• Reads the driver_additive_gen.ucf file and executes the ddlimp2 command it contains.
• The ddlimp2 command performs the following steps:
  • Reads the tables and indexes from the schema.ddl file.
  • Connects to the specified database and reads the existing schema and indexes.
  • Identifies the upgrade schema changes that can be made with the database online.
  • Writes these upgrade changes to the schema.additive.sql script.
  • Writes all actions to schema.additive.log.

The Upgrade Wizard does not execute schema.additive.sql against the database.

How to Use Additive Schema Changes

Use the following workflow to implement Additive Schema Changes:

1. In the production test environment, complete all development and upgrade testing. The schema.ddl file must be in its final form.
2. As part of running the Tuning Upgrade Performance process, restore the production test environment database to its original, unupgraded state.
3. Run the Database Server Configuration Utilities in Apply Additive Schema Changes mode, and generate the schema.additive.sql script.
4. Windows. You will not be prompted whether you want to run the Upgrade Wizard. Instead, the Upgrade Wizard starts automatically, and creates the schema.additive.sql script. The Upgrade Wizard does not run the script against the database.
5. UNIX. After the Database Server Configuration Utilities exit, run the Upgrade Wizard to generate the schema.additive.sql script. The Upgrade Wizard does not run the script against the database.
6. Review the schema.additive.log file. Verify that the script was created successfully.
7. Review the schema.additive.sql script. Verify that it will not make changes that conflict with customizations. Edit the script as required.
8. Use an SQL editor to apply the schema.additive.sql script to the database.
9. Verify that applications function normally. If necessary, revise schema.additive.sql and reapply it to the database.
10. Complete the remainder of the Tuning Upgrade Performance process. See Process of Tuning Siebel Upgrade Performance.
11. When you are ready to upgrade the production database, run the schema.additive.sql script against the production database before doing the production upgrep.
12. There is no need to then run database statistics. The schema changes are not useful for optimizing applications function before the upgrade.

The steps in this workflow have been incorporated into the process you use to perform both upgrade tuning and the production environment upgrade.

Related Topics

About the Siebel Database Configuration Utilities

About the Siebel Database Configuration Utilities