19 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 19-1 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 19-2 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 19-3 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 19-1 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.