Defining delete table access

Use the table access method processing options to determine how the delete process accesses each table included in the process. By default, Optim determines the best method to access a table, by performing either scan or key lookup. A scan reads all rows in a table at one time; whereas, a key lookup locates rows using a WHERE clause to search for primary or foreign key values. In general, a key lookup is used when a DBMS index is available, and a scan is used when an index is not available.

Use the primary key index analysis option to view which tables have a primary key, and optionally, to create indexes.

You can override the default method, but should do so only if the statistical information in the process report indicates the default method is inefficient.

  1. Access the table access method processing options, depending on the service type:
    Delete service
    1. Expand a folder in the Directory Explorer that contains the delete service, expand the Delete Services node, and double-click the delete service to edit.
    2. Select the Strategy tab.
    Archive service
    1. Expand a folder in the Directory Explorer that contains the archive service, expand the Archive Services node, and double-click the archive delete to edit.
    2. Select the Delete tab.
    3. Ensure that Defer delete after archive is not selected.
    4. Click Delete Strategy to open the Table Delete Strategy window.
  2. Define table access options, using one of the following methods:
    • To set an option for a single table, use the Access Method column drop-down list, or right-click the row that contains the table and click Access Method.
    • To set an option for all tables, right-click the table list and click Access Method > Set All.
  3. Save the delete service.


Feedback