Hybrid Aggregation Mode — also referred to as Hybrid BSO or simply Hybrid mode — is an Essbase storage and aggregation configuration introduced in Oracle Hyperion 11.1.2 that combines capabilities of both BSO (Block Storage Option) and ASO (Aggregate Storage Option) within a single database. In traditional BSO, parent member values are stored explicitly after calculation runs — requiring a calculation step before parent-level data is available for reporting. In standard ASO, data is stored at leaf level and parents aggregate dynamically at query time — no calculation step required, but write-back is not supported. Hybrid mode allows a BSO cube to designate specific non-leaf members as Hybrid aggregation members — whose values are aggregated dynamically at query time from stored block data, like ASO — while the cube retains full BSO write-back, member formula, and Calc Script capabilities. The result is a BSO cube that does not require a separate aggregation run for parent-level reporting while still supporting interactive data entry and complex business rule calculations.
Hybrid Mode Aggregation Architecture
| Member Type in Hybrid Mode | Storage | Aggregation | Typical Use |
|---|---|---|---|
| Stored leaf members | BSO block — physical data stored | Pre-stored in block after calculation | Leaf-level input data; calculated member results that are referenced by other calculations |
| Hybrid members (dynamic upper levels) | Not stored — aggregated at query time | Dynamic from leaf data — no calc step needed | Parent-level rollup members where users query consolidated values without calculation |
| Dynamic Calc members | Not stored — computed at query time from formula | Formula evaluated per query | Ratios, percentages, variance measures |
When Hybrid Mode Provides Value
Hybrid Aggregation Mode provides the most value in planning applications where upper-level aggregation performance is a user experience problem — specifically, where users who open a management-level entity form or summary report must wait for a calculation run to complete before they see current parent totals. Without Hybrid mode, parent totals in BSO cubes reflect the most recent explicit calculation; if the calculation has not been run since the last data entry, parents show stale values. With Hybrid mode enabled for the Entity dimension’s upper hierarchy, regional and group-level totals reflect current child data immediately, without requiring an aggregation run, because they are computed dynamically at query time.
Performance Considerations
Hybrid mode improves read performance for parent-level queries at the cost of increased query-time computation. In an environment where thousands of concurrent users are querying upper-level parents simultaneously, the dynamic aggregation computation for each query can create server-side CPU load that would not exist if the parents were pre-aggregated. The performance trade-off between eliminating the aggregation run step and the query-time aggregation overhead must be validated under realistic concurrent user load before Hybrid mode is enabled in a production application. Oracle recommends enabling Hybrid mode for dimensions with large member counts where BSO block aggregation performance degrades, and using it selectively for the dimensions where the performance benefit outweighs the query-time computation overhead.
What Goes Wrong in Practice
The most common Hybrid mode configuration error is enabling it for dimensions whose member structure does not support efficient dynamic aggregation — specifically, dimensions with complex member formulas at parent levels that are computationally expensive to evaluate at query time. When a parent-level formula involves cross-dimensional calculations or IF conditions that reference many child members, dynamic evaluation of that formula at every query is slower than pre-calculating and storing the result. Hybrid mode should be applied selectively to dimensions where parent members are simple rollups of children, not to dimensions where parent formulas are computationally complex.
How Loop Wise Solutions Evaluates Hybrid Mode
We evaluate Hybrid Aggregation Mode as a specific performance remediation option in EPM applications where aggregation run times are extending the close cycle or where parent-level query response times are degrading user adoption. The evaluation includes benchmarking before and after enabling Hybrid mode for the candidate dimensions, under representative concurrent user load, before recommending it for production deployment.
