Administrator > DB 2

Online Even More of the Time

DB2 UDB for z/OS Version 8 is ready when you are

May | June 2005 | by Kate Langdon

When your business is on the Internet, the store is never closed. That's good for business, but challenging for the applications and database technology. Outages are painful and even planned maintenance windows are an expensive commodity that may result in lost time and revenue. DB2* Universal Database* (UDB) for z/OS* Version 8 helps alleviate some of these concerns by increasing data availability. You can:

Stay online while changing data structures

Improve availability with design flexibility

Back up data faster without disruption

As an added benefit, using these new functions in the appropriate situations often results in improved performance and easier operations.

Data Structures

Changes to your database are inevitable. The increasing pace of market changes continues to drive new business requirements that impact your data structures. As the resultant application-development cycles get shorter, you must be able to make these changes quickly and more frequently, hence more opportunities for both planned and unplanned outages. At the same time, business on demand means not having any outages. DB2 UDB for z/OS V8 can help you meet these demands by allowing you to quickly make changes to your table and index definitions while the database remains up and running.

In previous versions of DB2 UDB for z/OS, changing data structures required a manual, cumbersome process during which the objects were unavailable and all applications had to be stopped. For example, to change a column type, you had to:

1. Unload the table data.

2. Drop the table and indexes.

3. Recreate the table with the new column type.

4. Recreate the indexes, views, triggers and any other related structures.

5. Redefine the authorizations for the table and related objects.

6. Reload the data.

7. Rebind all plans and packages related to that table.

8. Test that the objects and programs still work.

Version 8 eliminates this tedium. Now you can change the column type by issuing a simple SQL statement:

ALTER TABLE ALTER COLUMN column-name data-type

The table and related objects remain available to applications and other transactions. This new functionality is called online schema evolution.

As the resultant application-development cycles get shorter, you must be able to make these changes quickly and more frequently, hence more opportunities for both planned and unplanned outages. ... DB2 UDB for z/OS V8 can help you meet these demands by allowing you to quickly make changes to your table and index definitions while the database remains up and running.

Next page: >>