In This Section:
Essbase provides an aggregate storage kernel as a persistence mechanism for multidimensional databases. Aggregate storage databases enable dramatic improvements in both database aggregation time and dimensional scalability. The aggregate storage kernel is an alternative to the block storage kernel. Aggregate storage databases typically address read-only, “rack and stack” applications that have large dimensionality, such as the following applications:
Aggregate storage applications, which differ from block storage applications in concept and design, have limitations that do not apply to block storage applications. The following sections describe the differences.
See Naming Restrictions for Applications and Databases. Names reserved for tablespaces, cannot be used as application or database names:
Displayed in the Application Properties window and the Database Properties window in Administration Services. (Information not supported by or relevant to aggregate storage applications is not shown. For a description of aggregate storage-specific information, see the Oracle Essbase Administration Services Online Help for the Application Properties window and Database Properties window.)
Table 123. Outline Differences Between Aggregate Storage and Block Storage
On conversion from a block storage database, attribute dimension members are tagged as Dynamic Calc. On standard dimension members Dynamic Calc tags are converted and tagged as stored members, which changes the Members Stored value on the Dimensions tab of the Database Properties window in Administration Services.
Levels of restructure; see Aggregate Storage Database Restructuring.
Levels of restructure; see Optimizing Database Restructuring.
Table 124. Calculation Differences Between Aggregate Storage and Block Storage
Table 126. Data Load Differences Between Aggregate Storage and Block Storage
The loading of multiple data sources into aggregate storage databases is managed through temporary data load buffers.
Atomic replacement of the contents of a database
When loading data into an aggregate storage database, you can replace the contents of the database or the contents of all incremental data slices in the database.
Aggregate storage databases can contain multiple slices of data. Data slices can be merged.
In a date-time dimension, you can load data into level-0 members using supported date-format strings instead of member names.
Date-time dimension type is not supported.
Table 127. Query Differences Between Aggregate Storage and Block Storage
(See also Design Considerations for Attribute Queries.)
Considerations when querying data from a dimension that has multiple hierarchies. See Query Design Considerations for Aggregate Storage.
Table 128. Feature Differences Between Aggregate and Block Storage
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