Use Oracle 9i Summary Advisor To Better Manage Your Data Warehouse

Innovative Consulting, Inc., 2002intelligent solutions for your businessintelligent solutions for your business

Use Oracle9i Summary Advisor to Better Manage Your Data Warehouse

IOUG Live! 2003 Jeffrey ChanSession 417

Innovative Consulting, Inc., 2002

Agenda

• Background on Summary• Overview of Summary Management• Functionalities of Summary Advisor• Summary Advisor Basics• Invoking the DBMS_OLAP Package• Using the Summary Advisor Wizard• Interpret the Recommendations• Conclusion• Q&A


Background on Summary

• Needs for Summary– Speed up analytic queries

• Implementations of Summary– Prior to Oracle8i: Snapshot– Since Oracle8i: Materialized view and query

rewrite

• Benefits of Materialized Views– Improve queries performance– Transparency

• Costs of Materialized Views– Storage– Processing power (creation and refresh)


Overview of Summary Management

DimensionsDefines hierarchical relationships among columns in dimension tables

Materialized ViewsDisplays the properties of existing materialized views

Materialized View LogEnables incremental refresh of materialized views

Refresh GroupSets up a group of materialized views and schedules the refresh

Summary AdvisorRecommends which materialized views to create, retain, or drop


Functionalities of Summary Advisor

• Challenge– Running hundreds of reports, ad hoc

queries– Materialized views vary in size and

benefit

• Functionalities– Provide recommendations– Evaluate existing materialized views– Estimate size of materialized views– Generate DDL scripts to implement the

recommendations


User Scenarios

• Converting snapshots to materialized views– Generate a base line

• Implementing a new data warehouse or data mart– Be proactive about performance

• Ongoing support and maintenance– Look for improvements periodically


Summary Advisor Basics

DBMS_OLAPPackage

DBMS_OLAPPackage

RepositoryRepository

Summary Advisor Wizard

Summary Advisor Wizard

Structural StatisticsWorkload StatisticsOther Prerequisites

Structural StatisticsWorkload StatisticsOther Prerequisites

Recommendations

ReportsDDL Scripts

Recommendations

ReportsDDL Scripts


Prerequisites

• Structural Statistics– Fact tables, dimension tables, and materialized

views– Use the DBMS_STAT package

• Workload Statistics– SQL Cache– User Defined– Oracle Trace

• Other Prerequisites– Dimensional model– Dimension objects


DBMS_OLAP Package

• Validation– VALIDATE_DIMENSION– VALIDATE_WORKLOAD_CACHE– VALIDATE_WORKLOAD_USER– VALIDATE_WORKLOAD_TRACE

• Workload management– LOAD_WORKLOAD_CACHE– LOAD_WORKLOAD_USER– LOAD_WORKLOAD_TRACE

• Filter management– ADD_FILTER_ITEM


DBMS_OLAP Package

• Materialized view strategy recommendation– RECOMMEND_MVIEW_STRATEGY

• Reporting and script generation– GENERATE_MVIEW_REPORT– GENERATE_MVIEW_SCRIPT

• Estimating size of materialized view– ESTIMATE_MVIEW_SIZE


DBMS_OLAP Package

• Materialized view strategy evaluation– EVALUATE_MVIEW_STRATEGY

• Repository management– PURGE_WORKLOAD– PURGE_FILTER– PURGE_RESULTS


Summary Advisor Steps

1. Load a workload2. Apply a filter to a workload3. Select fact tables4. Specify materialized view retention list or

percentage5. Specify storage6. Run recommendation process7. Generate reports and DDL scripts8. Implement the recommendations9. Evaluate existing materialized views


Invoking the DBMS_OLAP Package

• Make sure prerequisites are met• Create Identifiers

VARIABLE workload_id NUMBER;

EXECUTE DBMS_OLAP.CREATE_ID(:workload_id);

VARIABLE filter_id NUMBER;

EXECUTE DBMS_OLAP.CREATE_ID(:filter_id);

VARIABLE run_id NUMBER;

EXECUTE DBMS_OLAP.CREATE_ID(:run_id);



• Load a User Defined Workload– Create a table for user defined workload

data– Insert user defined workload

INSERT INTO user_workload VALUES (

'SELECT SUM(s.quantity_sold) FROM sales s, products p

WHERE s.prod_id = p.prod_id and p.prod_category = ''Boys''

GROUP BY p.prod_category', 'SH', 'app1', 10, NULL, 5, NULL, NULL);

– Load user defined workload into the repositoryEXECUTE DBMS_OLAP.LOAD_WORKLOAD_USER

(:workload_id,DBMS_OLAP.WORKLOAD_NEW,DBMS_OLAP.FILTER_NONE, 'SH', 'USER_WORKLOAD');



• Loading a SQL Cache Workload– The SQL cache can be cleared (as

needed)ALTER SYSTEM FLUSH SHARED_POOL;

– Run reports and ad hoc queries to populate the SQL cacheSELECT SUM(s.quantity_sold)

FROM sales s, products p

WHERE s.prod_id = p.prod_id

GROUP BY p.prod_category;

– Load SQL cache workload into the repositoryEXECUTE DBMS_OLAP.LOAD_WORKLOAD_CACHE

(:WORKLOAD_ID, DBMS_OLAP.WORKLOAD_NEW, DBMS_OLAP.FILTER_NONE, NULL, 1);



• Using FiltersEXECUTE DBMS_OLAP.ADD_FILTER_ITEM

(:filter_id, 'FREQUENCY', NULL, 5, 10, NULL, NULL);

• Running the Recommendation ProcessEXECUTE DBMS_OLAP.RECOMMEND_MVIEW_STRATEGY

(:run_id, :workload_id, :filter_id, 100000, 50, NULL, NULL);



• Creating Summary Advisor ReportEXECUTE DBMS_OLAP.GENERATE_MVIEW_REPORT

('C:\summary\demo.html', :run_id, DBMS_OLAP.RPT_RECOMMENDATION);

• Generating SQL ScriptEXECUTE DBMS_OLAP.GENERATE_MVIEW_SCRIPT

('C:\summary\demo.sql', :run_id, 'EXAMPLE');

• Maintaining the RepositoryEXECUTE DBMS_OLAP.PURGE_RESULTS(:run_id);

EXECUTE DBMS_OLAP.PURGE_FILTER(:filter_id);

EXECUTE DBMS_OLAP.PURGE_WORKLOAD(:workload_id);


Summary Advisor Report

• Table of Contents


Summary Advisor Report

• Materialized View Recommendations


Using the Summary Advisor Wizard

• Welcome Screen



• Specify workload



• Select fact tables



• Retain summaries (as needed)



• Specify storage



• View/Modify Recommendations


Using the Summary

• View/Modify Recommendations



• Finish


Interpret the Recommendations

• Key items to look for in the outputs– Recommended actions– Performance gain– Storage cost– Benefit-to-cost ratio

• Use the procedure EVALUATE_MVIEW_STRATEGY to measure the utilization


Conclusion

• Background on Summary• Overview of Summary Management• Summary Advisor

– Functionalities– How it works– How to run it– How to interpret the recommendations

Innovative Consulting, Inc., 2002intelligent solutions for your businessintelligent solutions for your business

Use Oracle9i Summary Advisor to Better Manage Your Data Warehouse

IOUG Live! 2003Session 417

ThanksThanks

Jeffrey ChanTechnology ConsultantInnovative [email protected]

Jeffrey ChanTechnology ConsultantInnovative [email protected]

Use Oracle 9i Summary Advisor To Better Manage Your Data Warehouse

Technology

workload purge

workload values

summary advisor basics

refresh summary advisor

id group

id number

id variable filter

summary advisor steps