/LSA110/ LSA Basic Flow Extensions - Corporate Memory (CM) & Harmonization InfoSource
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 LSA110 that overcomes the shortcomings of PSA elements.
For general information about LSA Data Flow Templates please refer to
- SAP NetWeaver BW 7.30: LSA Data Flow Templates Series - I. Introduction
- SAP NetWeaver BW 7.30: LSA Data Flow Templates Series - II. LSA Basics for LSA Data Flow Templates
Description
The LSA110 template overcomes the shortcomings of PSA elements when storing load history by introducing a dedicated Layer known as the Corporate Memory (CM). The corporate memory provides for all unforeseeable or unlikely situations. The CM InfoProviders offer service level like a source system for initial loads. LSA 110 shows the standard range of LSA Layers. Further layers can be added if required.
LSA110 also introduces a harmonization layer InfoSource that makes it possible to separate standard data unification transformations from (master) data integration transformations. This increases transparency.
Picture 1: LSA110 conceptual view
Picture 2: LSA110 EDW Layers in BW 7.30
Picture 3: LSA110 Data Mart Layers in BW 7.30
Target Group
LSA110 is applicable for BWs that are built with the following in mind:
- Flexibility supporting unknown situations
- Safety and robustness – avoiding unwanted surprises
- Managing the growth of historical data
Note: Introducing a CM layer should always be considered with large, global BWs. But the simple template LSA110 is normally not suitable for designing data flows for these kinds of BW implementations! You should consider using the more complex LSA data flow templates instead.
Implementation Details
Acquisition Layer
- Built using PSA elements as with LSA100
- PSA elements can only be used for immediate inspection of data loads
- Data from PSA elements should be deleted regularly
Note: For more details, see the previous LSA data flow templates
Harmonization & Quality Layer
- Data unification transformations are separated from flow-specific harmonization transformations using a harmonization layer InfoSource
Note: For more details, see the previous LSA data flow templates
Corporate Memory Layer (CM)
- Write-optimized DataStore objects build the corporate memory layer.
- CM DataStore objects are defined at DataSource level
- CM DataStore objects should store all fields of a DataSource (comprehensiveness)
- Load history from PSA is stored 1:1 in terms of content. This means that adding information and transformations like compounding keys is ok
- CM DataStore objects and propagation DataStore objects add LSA unification information for loaded records (see LSA100)
- CM DataStore objects are located in addition to the daily data flows, loading InfoCubes (branch out services) to prevent load impacts and reduce human access and errors.
- Data from CM DataStore objects should be stored on NLS (near-line storage)
Propagation Layer
Note: For more details, see the previous LSA data flow templates
Business Transformation Layer
Note: For more details, see the previous LSA data flow templates
Reporting Layer
Note: For more details, see the previous LSA data flow templates
Virtualization Layer
Note: For more details, see the previous LSA data flow templates
