Set the custom folder property Visible to user to No for more information, see

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Managing Summary Folders 14-1

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Managing Summary Folders This chapter explains summary folders and how you manage them using Discoverer Administrator, and contains the following topics: ■ About folders and summary folders in Discoverer ■ What are summary folders? ■ What are Discoverer summary tables? ■ What are materialized views? ■ What is Automated Summary Management ASM ■ How does ASM work? ■ What are the prerequisites for creating summary folders with ASM? ■ What are the different ways to run ASM and when do you use them? ■ What is the ASM policy? ■ Why must you refresh summary data? ■ What happens when a summary folder is refreshed? ■ How to run ASM using the Summary Wizard ■ How to run ASM after bulk load using the Load Wizard ■ How to run ASM using the command-line interface ■ How to run ASM using a batch file and the operating system scheduler ■ How to configure the database for summary folders About folders and summary folders in Discoverer Discoverer uses two kinds of folders: ■ folders - represent data Discoverer folders are classified as simple, complex, or custom. For more information, see Chapter 6, Creating and Maintaining Folders . ■ summary folders - represent data that has been queried and the results saved for reuse Discoverer uses summary folders to improve query response times for end users. 14-2 Oracle Fusion Middleware Administrators Guide for Oracle Business Intelligence Discoverer What are summary folders? Summary folders are a representation of queried data created in Discoverer Administrator that has been saved for reuse. The data is stored in the database in one of the following depending on the edition of Oracle: ■ materialized views Discoverer uses materialized views to store summarized data in Oracle Enterprise Edition databases. ■ tables Discoverer uses tables to store summarized data in Oracle Standard Edition databases. The tables created by Discoverer to store summarized data are called Discoverer summary tables. For more information about Discoverer summary tables, see What are Discoverer summary tables? . Summary folders improve the response time of a query because the query accesses pre-aggregated and pre-joined data rather than querying against the detail database tables. You can also direct Discoverer to use summary folders based on tables containing summary data that have been created by another application. These tables are known as external summary tables. You can specify that Discoverer refreshes external summary tables. You can create summary folders in one of two ways: ■ using the Automated Summary Management ASM feature for more information, see What is Automated Summary Management ASM ■ manually for more information, see What is manual summary folder creation? The recommended method for creating summary folders in Discoverer is to use Automated Summary Management ASM. What are Discoverer summary tables? Discoverer summary tables are database tables created by Discoverer Administrator that contain summarized data. Discoverer summary tables contain pre-aggregated and pre-joined data, and can improve query performance in Discoverer Plus and Discoverer Viewer. Discoverer automatically recognizes when a summary table is available and rewrites the query to use the summary table. For more information, see What is query rewrite? . For example, when a query is run for the first time in Discoverer Plus it retrieves data from the detail tables. This may require a multiple table join and aggregation over thousands or millions of rows, which could take some time to complete. If Discoverer has created a suitable summary table, the same query retrieves data from the summary table and will return results in a few seconds. Both queries will produce the same results. For more information about Discoverer and rewriting queries to summary tables with Oracle Standard Edition databases, see Example illustrating the advantages of rewriting a query to use a summary table . Note: Circumstances sometimes prohibit the creation of materialized views and result in the creation of Discoverer summary tables when running against Oracle databases