Managing ILM ADO Parameters

You can customize your ADO environment with ILM ADO parameters described in Table 5-2.

Table 5-2 ILM ADO Parameters

Name	Description
`ENABLED`	The `ENABLED` parameter controls ADO background evaluation and execution. The default is enabled on (`TRUE` or `1`). The settings of `ENABLED` and the `HEAT_MAP` initialization parameters interact as follows: If the `HEAT_MAP` initialization parameter is set to `ON` and the `ENABLED` parameter is set to `FALSE` (`0`), then heat map statistics are collected, but ADO does not act on the statistics automatically. If the `HEAT_MAP` initialization parameter is set to `OFF` and the `ENABLED` parameter is set to `TRUE` (`1`), then heat map statistics are not collected and because ADO cannot rely on the heat map statistics, ADO does nothing. ADO behaves as if `ENABLED` is set to `FALSE`.
`RETENTION` `TIME`	The value for `RETENTION` `TIME` specifies the length of time that data of completed ADO tasks is kept before that data is purged. The default is `30` days.
`JOB` `LIMIT`	The value for `JOB` `LIMIT` controls the maximum number of ADO jobs at any time. The maximum number of concurrent ADO jobs is calculated as (`JOB` `LIMIT`)(number of instances)(number of CPUs for each instance). The default is `10`.
`EXECUTION` `MODE`	The value of `EXECUTION` `MODE` controls whether ADO executes in online or offline mode. The default is online.
`EXECUTION` `INTERVAL`	The value of `EXECUTION` `INTERVAL` determines the frequency that ADO initiates background evaluation. The default is `15` minutes.
`TBS` `PERCENT` `USED`	The value for `TBS_PERCENT_USED` parameter specifies the percentage of the tablespace quota when a tablespace is considered full. The default is `85` percent.
`TBS` `PERCENT` `FREE`	The value for `TBS_PERCENT_FREE` parameter specifies the targeted free percentage for the tablespace. The default is `25` percent.

For the values of the TBS_PERCENT* parameters, ADO makes a best effort, but not a guarantee. When the percentage of the tablespace quota reaches the value of TBS_PERCENT_USED, ADO begins to move data so that percent free of the tablespace quota approaches the value of TBS_PERCENT_FREE. As an example, assume that TBS_PERCENT_USED is set to 85 and TBS_PERCENT_FREE is set to 25, and that a tablespace becomes 90 percent full. ADO then initiates actions to move data so that the tablespace quota has at least 25 percent free, which can also be interpreted as less than 75 percent used of the tablespace quota.

You can display the parameters with the DBA_ILMPARAMETERS view. For example, the following query displays the values of the ADO-related parameters.

SQL> SELECT NAME, VALUE FROM DBA_ILMPARAMETERS;

NAME                                                             VALUE
---------------------------------------------------------------- ----------
ENABLED                                                                   1
RETENTION TIME                                                           30
JOB LIMIT                                                                10
EXECUTION MODE                                                            3
EXECUTION INTERVAL                                                       15
TBS PERCENT USED                                                         85
TBS PERCENT FREE                                                         25

7 rows selected.

You can set ILM ADO parameters with the CUSTOMIZE_ILM procedure in the DBMS_ILM_ADMIN PL/SQL package, as shown in Example 5-8. For information about setting ILM ADO parameters with Oracle Enterprise Manager Cloud Control, refer to "Managing ILM Heat Map and ADO with Oracle Enterprise Manager".