The following topics describe terms that are integral to an explanation of aggregate storage database calculation.
Cells for level 0 intersections across dimensions, without formulas, are called input cells. Data values can be loaded to them. Higher-level cells involving members of the accounts dimension or dynamic hierarchies are always calculated at retrieval. All other higher-level intersections across dimensions are aggregate cells. For example, for the outline in Figure 163, Sample Aggregate Storage Outline, Price Paid > Curr Year > 1st Half > Portable Audio > CO is an aggregate cell; Original Price > Curr Year > Jan > Camcorders > CO is another aggregate cell. Values for aggregate cells must be rolled up from lower-level values.
Aggregate cell values are calculated for each request, or they can be precalculated and stored on disk.
When Essbase defines which aggregate cells to precalculate and store, it works with aggregate views. An aggregate view is a collection of aggregate cells. The collection is based on the levels of the members within each dimension.
For example, consider one aggregate view for the outline in Figure 163, Sample Aggregate Storage Outline. This aggregate view includes aggregate cells for the following dimension levels:
The example aggregate view is shown as 0, 0, 1/0, 2/0, 0.
Each dimension is shown, left to right, in its sequence in the outline. If a dimension contains hierarchies, the notation specifies the member level within its hierarchy. Hierarchies within a dimension are numbered top-down, starting with hierarchy 0.
The 0, 0, 1/0, 2/0, 0 aggregate view contains aggregate cells that include the following member intersections:
Original Price, Curr Year, Qtr1, Personal Electronics, CO Original Price, Curr Year, Qtr1, Personal Electronics, KS Original Price, Curr Year, Qtr1, Home Entertainment, CO Original Price, Curr Year, Qtr1, Home Entertainment, KS Original Price, Curr Year, Qtr2, Personal Electronics, CO Original Price, Curr Year, Qtr2, Personal Electronics, KS Original Price, Curr Year, Qtr2, Home Entertainment, CO Original Price, Curr Year, Qtr2, Home Entertainment, KS Original Price, Curr Year, Qtr3, Personal Electronics, CO Original Price, Curr Year, Qtr3, Personal Electronics, KS Original Price, Curr Year, Qtr3, Home Entertainment, CO Original Price, Curr Year, Qtr3, Home Entertainment, KS Original Price, Curr Year, Qtr4, Personal Electronics, CO Original Price, Curr Year, Qtr4, Personal Electronics, KS Original Price, Curr Year, Qtr4, Home Entertainment, CO Original Price, Curr Year, Qtr4, Home Entertainment, KS Original Price, Prev Year, Qtr1, Personal Electronics, CO Original Price, Prev Year, Qtr1, Personal Electronics, KS Original Price, Prev Year, Qtr1, Home Entertainment, CO Original Price, Prev Year, Qtr1, Home Entertainment, KS and so on...
Aggregations are consolidations, based on outline hierarchy, of level 0 data values. An aggregation contains one or more aggregate views. Essbase provides an intelligent aggregation process that selects aggregate views to be rolled up, aggregates them, and then stores the values for the cells in the selected views. If an aggregation includes aggregate cells dependent on level 0 values that are changed through a data load, the higher-level values are automatically updated at the end of the data load process.
The term aggregation is used for the aggregation process and the set of values stored as a result of the process.
Each aggregation script is a file that defines a particular selection of aggregate views to be materialized. The Administration Services Aggregation Design Wizard enables you to create aggregation scripts and store them in the database directory as text files with the .csc extension. See Working with Aggregation Scripts.