18 DBMS_AUTOIM

This API provides functions to manage the execution of the AIM feature.

Using DBMS_AUTOIM

Automatic In-Memory Management (AIM) is an In-Memory column store feature that optimizes the column store through actions such evicting cold data, populating frequently accessed data, and compressing cold columns.

The DBMS_AUTOIM package provides APIs to manage the execution of the AIM feature. These are procedures to get and set AIM parameters as well as a reporting function.

Summary of DBMS_AUTOIM Subprograms

The table in this topic lists and describes the DBMS_AUTOIM subprograms.

Table 18-1 DBMS_AUTOIM Subprograms

Subprogram	Description
SET_PARAMETER	Sets the value of one of the available parameters: AUTO_IM_PERF_TASK, INTERVAL, or AIM_STATWINDOW_DAYS.
ACTIVITY_REPORT	Reports AIM task activity within the specified time interval for the given feature or for all features.

SET_PARAMETER Procedure

Use this DBMS_AUTOIM procedure to set configuration parameter values for AIM features.

Syntax

DBMS_AUTOIM.SET_PARAMETER( parameter_name IN VARCHAR2, parameter_value IN VARCHAR2 );

Parameters

The parameters for DBMS_AUTOIM.SET_PARAMETER are as follows.

Table 18-2 SET_PARAMETER Procedure Parameters

Parameter	Description
aim_task	Turns the automatic IM automatic performance feature creation task on or off. Values: enable, disable.
interval	Controls the statistics time window used by AIM to compute decisions. Value: Any positive integer representing the time window in seconds. The default is 900 seconds.

ACTIVITY_REPORT Function

Use this function to generate a report on the automatic creation of IM performance features. These features include Autonomous Join Groups, Autonomous Bloom Filter Optimization, Autonomous Optimized Arithmetic, and Autonomous Vector Optimization.

Syntax

DBMS_AUTOIM.ACTIVITY_REPORT( feature_id IN NUMBER, start_time IN TIMESTAMP, end_time IN TIMESTAMP, type IN VARCHAR2, level IN VARCHAR2 ) 

Table 18-3 ACTIVITY_REPORT Function Parameters

Parameter	Type	Description
feature_id	integer	A NULL feature_id generates report on all AIM features. The default is NULL. You can get the feature_id for each feature from the view V$AIM_FEATURES .
start_time	timestamp	Start of the time window in which AIM activities are considered for the report. A NULL start_time returns the report for last execution. Default is NULL.
end_time	timestamp	End of time window in which AIM activities are considered for the report. A NULL end_time returns the report for last execution. Default is NULL.
type	varchar2	Type of the report. Possible values are: 'TEXT', 'HTML', 'XML'. Default is 'TEXT'.
level	varchar2	Level of verbosity. Possible values are 'BASIC' and 'DETAILED'. Default is 'BASIC'.

Example 18-1 ACTIVY_REPORT function

Create an AIM activity report for the previous day in TEXT format. The return type is CLOB.

declare
   report clob := null;
   begin
       report := DBMS_AUTOIM.activity_report();
   end;

Note:

See the view V$AIM_FEATURES to obtain the feature_id for each feature.