Thursday, February 17, 2011

ASO and BSO

Summary Difference

The main difference between ASO and BSO as show you as below:
1. ASO can support large scale of member such as Customer individual analysis, for example if your customer dimension has 1M members, the aggregate calculation time will very faster than BSO.
2. ASO cannot support write-back but BSO can support that feature (Write-Back = Input data directly back to Essbase Cube)
3. ASO can support large scale aggregation but for another purpose such as what-if or allocation should use BSO.
4. For architecture of calculation, ASO use MDX script, BSO use Calc Script.
5. For Cube that have many dimension and more member, ASO can save storage space more than BSO
6. We can use in-line formula on BSO outline but ASO cannot use that
7) When you Add or Delete or changing the outline the entire data will remove.
8) There is no right back option.
9) In a standard Dimension + & ~ consolidation property only .In measure -,/,% other symbols are there..
10) Only one database for Application.
11) There are no Calculation scripts and formulas.
12) Two pass, Variance are not used in ASO.


Basic Difference between ASO/BSO

Aggregate storage applications differ from block storage applications in both concept and design.
Storage Kernel: Architecture that supports rapid aggregation, optimized to support high dimensionality and sparse data. It doesn’t have Dense/Sparse concepts.
Physical storage definition Through the Application Properties window,
Tablespaces tab in Administration Services.
Database creation migrate a block storage outline or define after application creation.
ASO Support only one Database.


Outline Differences between Aggregate Storage and Block Storage

1) Multiple hierarchies enabled, dynamic hierarchy, or stored hierarchy designation
2) No two-pass calculation
3) ASO does not have concept of Dense/Sparse.
4) Support for the ~ (no consolidation) operator (underneath label-only members only) and the + (addition) operator
5) Cannot have formulas
6) Restrictions on label only
7) No Dynamic Time Series members
8) Dynamic Calc and Store not relevant
9) No association of attribute dimensions with the dimension tagged as Accounts


Calculation Differences Between Aggregate Storage and Block Storage

1) Database calculation Aggregation of the database, which can be predefined by defining aggregate views
2) Calculation script is not supported by ASO. Only outline consolidation.
3) Formulas Allowed with the following restrictions:
4) Must be valid numeric value expressions written in MDX (cannot contain % operator, replace with expression: (value1/value2)*100)
5) No support for Essbase calculation functions
6) On dynamic hierarchy members, formulas are allowed without further restrictions.
7) Calculation order Member formula calculation order can be defined by the user using the solve order member property
8) Attribute calculations dimension Support for Sum


Data Load Differences Between Aggregate Storage and Block Storage

1)      In ASO level 0 cells whose values do not depend on formulas in the outline are loaded whereas in BSO data can be loaded at any level (other than Dynamic Calc).
At the end of a data load, if an aggregation exists, the values in the aggregation are recalculated automatically whereas in BSO it has to be explicitly call i.e calc all. Block storage No automatic update of values. To update data values you must execute all necessary calculation scripts.
2)      Aggregate storage databases can contain multiple slices of data. Data slices can be merged.
3)      The loading of multiple data sources into aggregate storage databases is managed through temporary data load buffers.


Creating Aggregate Storage Database, Application and Outline

There are 2 ways to create ASO cube
1)      Convert a block storage outline to an aggregate storage outline, and create an aggregate storage application to contain the converted database and outline.
2)      Create an aggregate storage application and database. The aggregate storage outline is created automatically when you create the database.

Stored Hierarchies
1)      Members of stored hierarchies are aggregated according to the outline structure. Because aggregate storage databases are optimized for aggregation, the aggregation of data values for stored hierarchies is very fast. To allow this fast aggregation, members of stored hierarchies have the following restrictions:
2)       Stored hierarchies can have the no-consolidation (~) operator (only underneath Label Only members) or the addition (+) operator.
3)       Stored hierarchies cannot have formulas.


Dynamic Hierarchies
               To evaluate a dynamic hierarchy, Essbase calculates rather than aggregates the members and formulas. The order in which members and formulas are evaluated is defined by the solve order property. At the time of retrieval, Essbase calculates the required member combinations and calculates any required outline member formulas. Because dynamic hierarchies are calculated, the data retrieval time may be longer than for data retrieved from stored hierarchies. However, when you design your database, dynamic hierarchies provide the following advantages

1)      Dynamic hierarchies can contain any consolidation operator.
2)      Dynamic hierarchies can have formulas.

Alternate Hierarchies
An alternate hierarchy may be modeled in either of the following ways:

As an attribute dimension, which uses attributes to classify members logically within the dimension (for example, a Product dimension can have attributes such as Size and Flavor.) As a hierarchy of shared members. The alternate hierarchy has shared members that refer to non shared members of previous hierarchies in the outline. The shared members roll up according to a different hierarchy from the non shared members to which they refer. Shared members on dynamic hierarchies can have formulas. The non shared instance of the member must occur in the outline before any shared instances of the member





2 comments:

  1. More informative..
    Detailed information...Good

    ReplyDelete
  2. Very good post , good choice of subtopics of ASO. very usefull.
    thanks

    ReplyDelete