98 DBMS_ILM_ADMIN

The DBMS_ILM_ADMIN package provides an interface to customize Automatic Data Optimization (ADO) policy execution. In combination with partitioning and compression, ADO policies can be used to help implement an Information Lifecycle Management (ILM) strategy.

This chapter contains the following topics:

See Also:

98.1 DBMS_ILM_ADMIN Overview

To implement your ILM strategy, you can use Heat Map in Oracle Database to track data access and modification. You can also use Automatic Data Optimization (ADO) to automate the compression and movement of data between different tiers of storage within the database.

98.2 DBMS_ILM_ADMIN Security Model

This package runs under definer's rights. The user requires DBA privileges.

98.3 DBMS_ILM_ADMIN Constants

The table in this topic describes constants used by the DBMS_ILM_ADMIN package.

The value column refers to the numeric or character value that the constants resolve to.

Table 98-1 DBMS_ILM_ADMIN Constants

Constant Value Type Description

ABS_JOBLIMIT

12

NUMBER

Specifies the absolute number of concurrent ILM ADO jobs.

DEG_PARALLEL

10

NUMBER

Decides the degree of parallelism to be used for ADO jobs

ENABLED

7

NUMBER

Provides a way to turn background ADO off or on

EXECUTION_INTERVAL

1

NUMBER

Determines the frequency with which ADO background evaluation occurs. Specified in minutes.

EXECUTION_MODE

4

NUMBER

Controls whether ADO execution is online, offline. The value for this parameter should either be DBMS_ILM_ADMIN.ILM_EXECUTION_OFFLINE or DBMS_ILM_ADMIN.ILM_EXECUTION_ONLINE.

HEAT_MAP_SEG_LOOKUP

8

NUMBER

Index scan done

HEAT_MAP_SEG_READ

1

NUMBER

Segment read done

HEAT_MAP_SEG_SCAN

4

NUMBER

Full table scan done

HEAT_MAP_SEG_WRITE

2

NUMBER

Segment write done

JOB_SIZELIMIT

13

NUMBER

Specifies the size (in megabytes) of the data that is processed by a single ILM ADO row level compression job.

JOBLIMIT

5

NUMBER

Controls the upper limit on number of ILM ADO jobs at any time. The maximum number of concurrent ADO jobs is JOBLIMIT*(number of instances)*(number of CPUs per instance).

POLICY_TIME

11

NUMBER

Decides if ADO policies are treated as though they are specified in seconds rather than days. Can take value ILM_POLICY_IN_SECONDS (treat policy time in seconds) or ILM_POLICY_IN_DAYS (treat policy time in days - default).

RETENTION_TIME

2

NUMBER

Controls the amount of time ADO history should be maintained. Specified in days.

TBS_PERCENT_FREE

9

NUMBER

Decides the targeted tablespace storage through ADO actions as a percentage of tablespace quota.

TBS_PERCENT_USED

8

NUMBER

Decides when a tablespace is considered full. Specified as a percentage of tablespace quota.

The DBMS_ILM_ADMIN package uses the constants as parameter values shown in Table 98-2.

Table 98-2 DBMS_ILM_ADMIN Constants Used as Parameter Values

Constant Value Type Description

AUTO_OPTIMIZE_ENABLED

15

NUMBER

Indicates whether automatic storage compression is enabled.

AUTO_OPTIMIZE_INACTIVITY_THRESHOLD

14

NUMBER

The period of inactivity that will determine that there are no modifications. This can be specified using DBMS_ILM_ADMIN.CUSTOMIZE_ILM. The default value is 1440 minutes, which is 1 day.

ILM_DISABLED

2

NUMBER

Indicates automatic ADO policy evaluation and execution is disabled

ILM_ENABLED

1

NUMBER

Indicates automatic ADO policy evaluation and execution is enabled

ILM_EXECUTION_OFFLINE

1

NUMBER

Specifies that the object may be offline while ADO action is performed.

ILM_EXECUTION_ONLINE

2

NUMBER

Specifies that the object should be online while ADO action is performed

ILM_POLICY_IN_DAYS

0

NUMBER

Indicates policy is specified in days. This is the default.

ILM_POLICY_IN_SECONDS

1

NUMBER

Indicates policy unit is changed from days to seconds. This could be used to test ADO policy evaluation quickly instead of waiting for the policy duration.

Note:

  • Setting ILM_POLICY_IN_SECONDS does not compress the blocks within the specified seconds.
  • Setting ILM_POLICY_IN_SECONDS is for test ADO and should not be set in the production environment.

98.4 Summary of DBMS_ILM_ADMIN Subprograms

This table lists and briefly describes the DBMS_ILM_ADMIN package subprograms.

Table 98-3 DBMS_ILM_ADMIN Package Subprograms

Subprogram Description

CLEAR_HEAT_MAP_ALL Procedure

Deletes all rows except the dummy row

CLEAR_HEAT_MAP_TABLE Procedure

Clears all or some statistics for the heat map table, deleting rows for a given table or segment which match a given pattern, or all such rows

CUSTOMIZE_ILM Procedure

Customizes environment for ILM execution by specifying the values for ILM execution related parameters

DISABLE_ILM Procedure

Turns off all background ILM scheduling

ENABLE_AUTO_OPTIMIZE Procedure Enables Auto Compression for all Hybrid Columnar Compression objects in the PDB.

ENABLE_ILM Procedure

Turns on all background ILM scheduling

IGNORE_AUTO_OPTIMIZE_CRITERIA Procedure Ignores the inactivity threshold so that uncompressed loads will be eligible for background auto optimization immediately.

SET_HEAT_MAP_ALL Procedure

Updates or inserts heat map rows for all tables

SET_HEAT_MAP_START Procedure

Sets the start date for collecting heat map data

SET_HEAT_MAP_TABLE Procedure

Updates or inserts a row for the specified table or segment

98.4.1 CLEAR_HEAT_MAP_ALL Procedure

This procedure deletes all rows in HEAT_MAP_STAT$ except the dummy row.

Syntax

DBMS_ILM_ADMIN.CLEAR_HEAT_MAP_ALL;

98.4.2 CLEAR_HEAT_MAP_TABLE Procedure

This procedure clears all or some statistics for the heat map table, deleting rows for a given table or segment which match a given pattern, or all such rows.

Syntax

DBMS_ILM_ADMIN.CLEAR_HEAT_MAP_TABLE  (
   owner                   IN  VARCHAR2,
   tablename               IN  VARCHAR2,
   partition               IN  VARCHAR2 default '',
   access_date             IN  DATE DEFAULT NULL,
   segment_access_summary  IN  NUMBER DEFAULT NULL);

Parameters

Table 98-4 CLEAR_HEAT_MAP_TABLE Procedure Parameters

Parameter Description

owner

Table owner

tablename

Table name

partition

Name of the subobject, defaults to NULL

access_date

Date for the entry in HEAT_MAP_STAT$ to be removed

segment_access_summary

Summary of segment access constants indicating access operations performed on the segment

98.4.3 CUSTOMIZE_ILM Procedure

This procedure customizes environment for ILM execution by specifying the values for ILM execution related parameters. These values take effect for the next background scheduling.

Syntax

DBMS_ILM_ADMIN.CUSTOMIZE_ILM  (
   parameter            IN       NUMBER,
   value                IN       NUMBER);

Parameters

Table 98-5 CUSTOMIZE_ILM Procedure Parameters

Parameter Description

parameter

One of the parameter constants defined in DBMS_ILM_ADMIN package

value

Value of parameter

98.4.4 DISABLE_AUTO_OPTIMIZE Procedure

Disables Auto Compression for all Hybrid Columnar Compression objects in the PDB.

Syntax

After you issue enable_auto_optimize, auto compression will be enabled. New direct loads will be in an uncompressed format and the data will be compressed gradually in the background. For example, after five direct loads the user issues disable_auto_optimize. If the background auto compression task was only able to compress three of them (because of autotask time constraints, data not yet cold, etc.), the remaining two will be in an uncompressed format. The data from these two uncompressed loads will be compressed in the background even after the user issues disable_auto_optimize, but new direct loads will now be compressed.

DBMS_ILM_ADMIN.DISABLE_AUTO_OPTIMIZE;

98.4.5 DISABLE_ILM Procedure

This procedure turns off all background ILM scheduling.

Syntax

DBMS_ILM_ADMIN.DISABLE_ILM;

98.4.6 ENABLE_AUTO_OPTIMIZE Procedure

Enables Auto Compression for all Hybrid Columnar Compression objects in the PDB.

Syntax

When Auto Compression is enabled, direct loads into a Hybrid Columnar Compression (HCC) object would use the uncompressed format to achieve faster loads. The system will then wait until there are no modifications to the newly loaded data, for the duration of the specified inactivity threshold. At that point, the data from the uncompressed direct load will be gradually HCC compressed using a background Auto Compression task.

DBMS_ILM_ADMIN.ENABLE_AUTO_OPTIMIZE;

98.4.7 ENABLE_ILM Procedure

This procedure turns on all background ILM scheduling.

Syntax

DBMS_ILM_ADMIN.ENABLE_ILM;

98.4.8 IGNORE_AUTO_OPTIMIZE_CRITERIA Procedure

Ignores the inactivity threshold so that uncompressed loads will be eligible for background auto optimization immediately.

Syntax

DBMS_ILM_ADMIN.IGNORE_AUTO_OPTIMIZE_CRITERIA;

98.4.9 SET_HEAT_MAP_ALL Procedure

This procedure sets an HTTP request header. The request header is sent to the Web server as soon as it is set.

Syntax

DBMS_ILM_ADMIN.SET_HEAT_MAP_ALL  (
   access_date            IN DATE,
   segment_access_summary IN NUMBER);

Parameters

Table 98-6 SET_HEAT_MAP_ALL Procedure Parameters

Parameter Description

access_date

Date for the entry in HEAT_MAP_STAT$ to be added

segment_access_summary

Summary of segment access constants indicating access operations performed on the segment

98.4.10 SET_HEAT_MAP_START Procedure

This procedure sets the start date for collecting heat map data.

Syntax

DBMS_ILM_ADMIN.SET_HEAT_MAP_START  (
   start_date  IN   DATE);

Parameters

Table 98-7 SET_HEAT_MAP_START Procedure Parameters

Parameter Description

start_date

Indicates the new date from which all statistics are valid

98.4.11 SET_HEAT_MAP_TABLE Procedure

This procedure updates or inserts a row for the specified table or segment.

Syntax

DBMS_ILM_ADMIN.SET_HEAT_MAP_TABLE  (
   owner                  IN VARCHAR2,
   tablename              IN VARCHAR2,
   partition              IN VARCHAR2 DEFAULT '',
   access_date            IN DATE DEFAULT NULL,
   segment_access_summary IN NUMBER DEFAULT NULL);

Parameters

Table 98-8 SET_HEAT_MAP_TABLE Procedure Parameters

Parameter Description

owner

Table owner

tablename

Table name

partition

Name of the subobject, defaults to NULL

access_date

Date for the entry in HEAT_MAP_STAT$ to be added

segment_access_summary

Summary of segment access constants indicating access operations performed on the segment