ACM

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There are two forms of the ACM command. One is used to display the Choose Access Method panel; the other is used to specify the access method for all tables on the Choose Access Method panel.

Access the Choose Access Method panel

Modify the default method (scan or key lookup) used to access tables for processing and, if key lookup is the default method, specify the maximum number of key lookups performed at one time to increase Archive, Delete, Extract, Insert, and Restore performance.


ACM
  • This command is valid from the following panels:
    • The Specify Relationship Usage panel for an Archive or Extract Process.
    • The Process Table Map panel for a Compare, Insert, or Restore Process, as well as from the Define or Modify Table Map panel.
    • The Specify DELETE Parameters and Execute (from the Data Migration menu) or the Delete Rows from Archive Process (from the Archive and Restore menu), as well as the Specify ARCHIVE Parameters and Execute panel, if the Defer Delete after Archive option is set to Y.
  • From the Specify Relationship Usage panel, the Choose Access Method / Key Lookup Limit pop-up window is displayed listing each relationship selected in the Access Definition. From this window you can override the default access method and specify the maximum number of simultaneous key lookups used when processing rows for each relationship in the Access Definition.
  • From a Table Map editor, the Choose Access Method pop-up window is displayed listing the names of all the destination tables in the Table Map. From this window you can override the default access method used to process rows to the destination tables specified in the Table Map.
  • For the Delete Process, the Choose Access Method / Key Lookup Limit pop-up window is displayed listing the names of all the tables in the Archive or Extract File. From this window, you can override the default access method and specify the maximum number of simultaneous key lookups used when deleting rows for each table in the Archive File.

Set the Access Method


ACM  [  B | K | S ]

From any Choose Access Method panel, you can set the access method for all listed tables. Use the ACM command with one of the following operands:

B - Blank
The Archive, Extract, or Delete process automatically determines whether to use a table scan or key lookup.
K - Key Lookup
Force the process to use a key lookup to locate rows by using a WHERE clause to search for primary or foreign key values.
S - Table Scan
Force the process to read all rows in a table at one time.

For example, enter ACM B to clear the access method for all listed tables.