Design and Components of
Aggregates
On the Maintaining Aggregates screen in the Display of Aggregates and Their Components screen area, the aggregates and their components are displayed in a logical tree structure.
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 useful:
● 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.
● Whether aggregates are missing: Create new aggregates.
● Whether existing aggregates are still being used: Delete unnecessary aggregates.
The aggregates display in the Maintenance for Aggregate screen helps you to evaluate aggregates.
Column |
Information |
Aggregates |
Aggregates with all transferred components in a tree display |
Technical Name |
Technical name of the aggregate. |
Save |
|
Proposed Action |
The system proposes actions, as required.
Once the
system has proposed a new aggregate, it recommends that you activate this
aggregate. This is marked by |
Status |
|
Filled/Switched Off |
|
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 applicable. |
● Hierarchy Level |
Level of the hierarchy you have selected, where applicable. |
● Fixed Value |
Fixed value you have selected, where applicable. |
Valuation
|
Representation in a bar chart: ● The greater 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 provides information about the size of the aggregate. |
Records Summarized (Mean Value) |
Number of records read on average from the source to create a record in the aggregate.
This example is based on an aggregate with three records. 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 "compressed records". This provides information about the quality of the aggregate. ● The greater the value, the greater the compression and better the quality of the aggregate.
Since an aggregate should be 10 times smaller than its source, the number should be larger than 10. ● If the value is one, the aggregate is a copy of the InfoCube. In this case, consider deleting the aggregate. |
Use |
Number of uses (in queries). How often is the aggregate used for reporting? |
Last Used |
Date When was the aggregate last used in 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 change run. |
Last Roll Up |
Date When was data last entered for the aggregate? |
Last Roll Up By |
User name of the person who scheduled roll up. |
Last Changed On |
Date When was the aggregate definition last changed? |
Last Changed By |
User name of the person who last changed the aggregate. |
Integration
Log display
When you have defined the aggregate and filled it with data, the log display is shown in the lower part of the screen.
Status overview of aggregates
There is 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
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
for a particular aggregate, the Aggregate Display
screen appears. The
aggregate is displayed here together with its components.