Access Definitions

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An Access Definition defines a set of related data to be processed by Optim.

Use an Access Definition to select a set of related data that

  • Archive copies to an Archive File or restores to a database.
  • Move or Compare copies to an Extract File for processing.
  • Access displays for browsing or editing.

The components of an Access Definition are

  • A list of tables or views (i.e., the Table List).
  • Selection criteria in the form of WHERE predicates, substitution variables, Point-and-Shoot, and or row list designations.
  • Archive Actions to be performed before or after a row is archived, deleted, or restored.
  • Processing criteria in the form of row limits and selection factors.
  • A list of relationships among the listed tables and instructions for traversing them.
  • Optional instructions for displaying data for Point-and-Shoot, browsing, or editing.
  • Parameter settings to establish how the Access Definition is applied and to limit modifications to it during use.

In addition, the Access Definition editor includes several features to help you analyze and tune processing.

  • Show Steps lets you analyze a process before running it to ensure that the data processed and the traversal paths used to process the data are as you expect.
  • The Relationship Index Analysis feature analyzes DBMS indexes for selected relationships in the Access Definition, allowing you to create needed indexes to enhance performance.

You can define a temporary or permanent Access Definition for processing data. A permanent Access Definition is stored in the Optim Directory. For an Extract or Archive Process, a temporary Access Definition is discarded after the data is extracted. For a Compare Process, a temporary Access Definition is a “LOCAL” definition stored with the current Compare Definition, and it is available only for that Compare Definition.

Creating an Access Definition

A series of panels guides you through the process of creating or modifying an Access Definition. These panels are referred to collectively as the Access Definition editor. You can invoke the Access Definition editor independently, by selecting Option 5 (or 6.5) ADS from the Main Menu, or while preparing to execute an Archive, Compare, or Extract Process. (Each process is invoked from the Main Menu. For details about each process option, see the appropriate User Manual.)

The features and methods used to create an Access Definition are the same as those used to modify an existing Access Definition. You can initiate the creation of an Access Definition by providing a name that is not in use when displaying the Access Definition editor. Alternatively, you can edit an existing Access Definition in the Access Definition editor and save it under a new name.

Consider Purpose

When creating an Access Definition, it is important to consider the purpose of the Access Definition and who is to use it. An Access Definition can be used with Archive to archive data, with Access to browse or edit data, with Move to extract data, or with Compare to select data for comparison. However, if Access Definitions are shared among the Optim components, care must be taken to avoid changes that inadvertently affect other users of Optim. For example, if an Access user modifies an Access Definition established by a Move user, the Move user might then extract an unexpected set of data.

In addition, an Access Definition used by Move, Compare, or Archive does not allow duplicate references to a table, whether direct or indirect (for example, a reference to a view, synonym, or alias for a listed table). Access permits duplicate references.