Design and Components of Aggregates (SAP Library

Design and Components of Aggregates

Definition

Screen area of the Maintenance for Aggregates screen in which aggregates and their components are displayed in a logical tree.

Use

This screen area is used to:

· Define aggregates

· Obtain information about the status of individual aggregates

You can define several aggregates for an InfoCube. However, make sure that this is worthwhile:

· Advantage: Aggregates improve the performance of queries

· Disadvantage: Aggregates increase load time

¡ when uploading data packages

¡ during the hierarchy/attribute change run after loading master data

¡ when modifying time-dependent aggregates.

To optimize an InfoCube, you should repeatedly check:

· Whether aggregates are missing: Create new aggregates

· Whether existing aggregates are no longer being used: Delete unnecessary aggregates

The aggregates display in the Maintenance for Aggregate screen helps you to evaluate aggregates.

Structure

Column	What You Need to Know
Aggregates	Aggregates with all transferred components in a tree display
Technical name
Save	Marks new or changed aggregates
Proposed action	The system proposes actions if necessary Once the system has proposed a new aggregate, it recommends that you activate this aggregate. This is marked by in this column.
Status	Created Changed (The modified aggregate definition is no longer the same as the active aggregate definition) Saved and active
Filled/switched off	Not filled with data Filled with data
Individual components in the aggregate (see Selection Type (BW-WHM)):	By default, the system aggregates according to the values of the selected objects: · '*' All characteristic values · 'H' Hierarchy level · 'F' Fixed value In the context menu of the selection type, you can change this setting.
· Hierarchies	Name of the hierarchy you have selected, where relevant.
· Hierarchy level	Level of the hierarchy you have selected, where relevant.
· Fixed value	Fixed value you have selected, where relevant.
Valuation	Representation in a bar chart: · The larger the number of minus signs, the worse the evaluation of the aggregate: "-----" means: Aggregate can potentially be deleted. · The larger the number of plus signs, the better the evaluation of the aggregate: "+++++" means: Aggregate potentially very useful. The evaluation is based on a number of criteria. The following criteria are currently used in the evaluation: · How does the compression of the data compare with the InfoCube: How much smaller is the aggregate compared to the InfoCube? · When was the aggregate last used? (See under Last Used).
Records	Number of records in the filled aggregate. This information tells you something about the size of the aggregate.
Records summarized (mean value)	Number of records read on average from the source in order to create a record in the aggregate. This example is based on an aggregate with three records. For example, if 10 records are read for the first record in the aggregate, 15 records are read for the second record and 20 records are read for the third record, the aggregate has a mean of 15 "records compressed". This information tells you something about the quality of the aggregate. · The larger the value, the greater the compression and the better the quality of aggregate. Since an aggregate should be 10 times smaller than its source, the number should be larger than 10. · If the value is "1", the aggregate is a copy of the InfoCube. In this case, consider deleting the aggregate.
Use	Number of uses (in queries). How often has the aggregate been used for reporting?
Last used	Date When was the aggregate last used for reporting? If an aggregate has not been used for a long time, deactivate or delete it. Note that certain aggregates cannot be used at certain times (for example during vacation). Do not delete basic aggregates that you created to speed up the hierarchy/attribute change run.
Last rollup	Date When was the last time that data was entered for the aggregate?
Last rollup by	User name of the person who scheduled the rollup.
Last changed on	Date When was the aggregate definition last changed?
Last changed by	User name of the person who made the last change.

Integration

When you define the aggregate and after you have filled with data, the log display is shown in the lower part of the screen.

Status overview of aggregates

You can find a status display for all the aggregates in the BI system in the Administration functional area of the Data Warehousing Workbench:

In the navigation pane, under Monitors, choose This graphic is explained in the accompanying text Aggregates. The Status of the Aggregates screen area lists all the InfoCubes and all the existing aggregates under each InfoCube.

The structure of this screen area corresponds to the Aggregate screen area of the Maintenance for Aggregate screen. Only the status of the aggregates is displayed, not their components.

By double-clicking on This graphic is explained in the accompanying text of a particular aggregate, the Aggregate Display screen appears. The aggregate is displayed here together with its components.