Currently Being Moderated

/LSA300/ LSA Tactical Scalability - Flow Split using Semantic Partitioning

 

Background

With the new Data Flow Template feature it is now possible describing LSA standards directly in BW.

With BW 7.30 there comes a set of 10 LSA data flow templates as an initial offering.

This blog describes the LSA Data Flow Template LSA300 that handles situations where a single InfoProvider cannot guarantee the required service levels.

For general information about LSA Data Flow Templates please refer to

Description

LSA300 illustrates how to deal with situations where a single InfoProvider cannot guarantee the required service levels. Violation of service levels may be caused by the following:

  • Poor load performance (-> report availability)
  • Poor query performance with ROLAP
  • Long recovery time (-> report availability)
  • Lack of robustness (-> report availability)
  • Master data consistency issues (-> referential integrity)
  • Overall manageability issues of large InfoProviders
  • Other reasons 

The LSA suggest using the best practice modeling pattern ‘semantic partitioning’ of an InfoProvider if it is difficult to achieve a certain service level like ‘report availability at 8h local time’. Semantic partitioning is a very popular modeling pattern in BW. Instead of storing data in a single InfoCube or DSO, it means distributing the data into several identical InfoCubes or DataStore objects, thus splitting the affected flow. Either organizational or time characteristics serve as semantic partitioning criteria. 

Note: Semantic partitioning with a time characteristic does not normally speed up data loads.

With BW 7.30, the new Semantically Partitioned Object (SPO) supports the semantic partitioning of InfoProviders. Template LSA300 uses the new SPO feature, but the flow logic can also be used with older BW releases.

 

 

 

LSA300-conceptual

Picture 1: LSA300 conceptual view

LSA300-EDW-BW

Picture 2: LSA300 EDW Layers in BW 7.30

LSA300-DM-BW

Picture 3: LSA300 Data Mart Layers in BW 7.30

 

LSA300 assumes that service level issues occur only with specific InfoProviders.  The LSA calls a semantic partitioning ‘tactical’ if only a dedicated InfoProvider is semantically partitioned. Unlike this ‘tactical’ semantic partitioning the LSA Data Domains define a ‘strategic’ semantic partitioning, which applies to all or a large range of the data flows.

Note: Semantic partitioning does not solve modeling and implementation issues! 

Target Group

LSA300 can be used for all InfoProviders

  • Where service level achievement is a problem
  • Where service level achievement issues are restricted to a specific scenario (tactical level).

 

Note:  For large/global BWs, the tactical semantic partitioning approach is not sufficient.

Instead, the BW (the transactional InfoProviders) should be structured in terms of a common ‘strategic’ semantic partitioning approach defined by the LSA data domains (see LSA400)

 

Implementation Details

Acquisition Layer

Note: For more details, see the previous LSA data flow templates

Harmonization & Quality Layer

  • Tactical semantic partitioning can be modeled for any InfoProvider on any layer.
  • Tactical semantic partitioning is normally performed at reporting layer level. 

Note: For more details, see the previous LSA data flow templates

Corporate Memory Layer (CM)

The corporate memory DataStore objects are normally not semantically partitioned. If you are confronted with volume issues because of a missing data life cycle strategy, you could think about a semantic partitioning with a time characteristic.

Note: For more details, see the previous LSA data flow templates 

Propagation Layer

  • Tactical semantic partitioning can be modeled for any InfoProvider on any layer.
  • Tactical semantic partitioning is normally performed at reporting layer level. 

Note: For more details, see the previous LSA data flow templates 

Business Transformation Layer

  • Tactical semantic partitioning can be modeled for any InfoProvider on any layer.
  • Tactical semantic partitioning is normally performed at reporting layer level.

Note: For more details, see the previous LSA data flow templates

Reporting Layer

Tactical semantic partitioning can be modeled for any InfoProvider on any layer.

Tactical semantic partitioning is normally performed at reporting layer level.  Note the following:

  • Only parts of the flow are split
  • The condition (log. partitioning by time or organizational criteria, or both) that defines the split of an InfoProvider (how the data is distributed across multiple identical InfoProviders) is defined according to the required service target. It might therefore differ from scenario to scenario and from data flow to data flow.
  • BW 7.30 offers the semantically partitioned object (SPO) as functionality to set up semantically partitioned InfoCubes or DataStore objects.

For more details, see the previous LSA data flow templates

Virtualization Layer

Note: For more details, see the previous LSA data flow templates

Comments

Actions

Filter Blog

By date: