Data Acqusition

September 21, 2010 TCS Public

SAP BI

AcquisitionZaheer Abbas -

311733

September 21, 2010 2

SAP BI Data Acquisition -

Content

Data Flow in the BW Data Acquisition

Transformations in BW

Enhancing BW Data Sources

Delta Management

Transfering Data from Flat Files

Define and manage Process Chains


Data Flow in SAP BIDefinitionIt shows the flow of data from the source system to the InfoProvider where it gets readied for use in the reports. Simply put together the data flow is the path that data have to follow (among several stages and provider) in order to have all the info available for final reporting purpose.

Sample Data Flow Screen


DatasourcesDefinitionSAP describes Datasource as Data that logically belongs together is stored in the source system in the form of DataSources. So to say that DataSources are used for extracting data from a source system and for transferring data into BI. Sample Data Flow Screen

1) DataSources are used to extract and stage data from source systems. The DataSource can be used for all objects that contain data i.e. Master data (Attribute, Text, and Hierarchy) and Transactional data.2) Or for that matter the data is loaded into BI from any source in the DataSource structure.3) The structure for transferring data from a DataSource to SAP BW is called transfer structure (we will discuss this later in the class under the same topic)5) An InfoPackage is used for this purpose. You determine the target into which data from the DataSource is to be updated during the transformation. You also assign DataSource fields to target object InfoObjects in BI.6) SAP R/3 systems provides a number of SAP Business Content DataSources that can be used immediately.


Persistent Staging AreaDefinitionPSA (Persistent Staging Area) is an inside storage place where the data is stored in an unchanged form from the source systems.

- Info Package's load the data from the source into the PSA

InfoPackages are meant for scheduling the load and they send a request Idoc to the source system to fetch the data. You would create InfoPackages for each of the source system

- Is stored in Transfer Structure format as a transparent PSA table is created for every Data Source that is activated.

- In the relational database tables as in BW systems, the PSA tables each have the same structure as their respective Data Source

- Data is not summarized/transformed and the duration of the data storage in the PSA is medium-term.


Transfer RulesDefinition and Purpose

The transfer rules transform and clean up the data from the PSA. Transfer rules determines how the mapping is done from the Datasource fields to the InfoSource InfoObjects. Transfer rules are dependent on the source system data and reflect the same The no. of transfer rules would be equal to the no. of source system for a data target Transfer rules is mainly for data cleansing and data formatting after the data arrives in the activation queue Here the transfer structure and the communication structure are maintained You use the transfer rules to determine how you want the transfer structure fields to be assigned to the communication structure InfoObjects. You can arrange for a 1:1 assignment. You can also fill InfoObjects using routines, formulas, or constants.


Update Rules

Concept & PurposeUpdates Rules

- Generally, the update rules are only used here for one-to-one transfer into the ODS object - Update rules contain the business logic and its nature depends on how we want the data target i.e. InfoCube to be. - Update rules specify how the data (key figures, time characteristics, characteristics) is updated into the InfoProvider from the communication structure. - Update rules are Data target dependant - In Update rules you would write the business rules (called routines which in done in ABAB) for your data target for e.g. Currency translations are possible in update rules and some other more complex computations. - If you would want to split a single record into multiple values, return table is an ideal solution in update rules (we will not discuss return table here as it is an advanced topic). For e.g.: We have sales revenue value for a particular customer. Now if it is needed to be split into percentages based on an additional character say segment (and this not a standard field in R/3), the single record with one value per customer can be split into these percentages using the return table.


Infopackage

- 1) When you trigger the info-package it sends a request to the source system to start the extraction process and this corresponds to the step "Data Request Received" in monitor under details tab. It is the first step.

2) Then the selections specified in the info-package are transferred to the source system to select the requested data from BW system. Then it is sent back to BW system.

3) Once it reaches BW, it gets into the PSA and then it gets updated into the data target (depends on what settings are made in IP). No rule (Transfer rules / update rules) comes into picture when data is stored in PSA. Only the transfer structure is used to map the BW info-objects with the source system fields.

4) After data is stored into PSA, the update into the data targets begins. First the transfer rules are applied -> data then flows through the communication structure -> update rules are applied and finally the records gets updated into the data target.


SAP BI 3.5 Extraxtion

Flow

The extraction flow is: - Source System (DS) -> PSA -> Transfer Rules -> Communication Structure -> Update Rules -> Data target.

Info-package actually triggers the whole data flow in BW system.


Transformation in SAP BIThe transformation process allows you to consolidate, cleanse, and integrate data. You can semantically synchronize data from heterogeneous sources.When you load data from one BI object into a further BI object, the data is passed through a transformation. A transformation converts the fields of the source into the format of the target. A transformation consists of at least one transformation rule. Various rule types, transformation types, and routine types are available. These allow you to create very simple to highly complex transformations:

Transformation rules: Transformation rules map any number of source fields to at least one target field. You can use different rules types for this.

Rule type: A rule type is a specific operation that is applied to the relevant fields using a transformation rule.

Transformation type: The transformation type determines how data is written into the fields of the target.

Rule group: A rule group is a group of transformation rules. Rule groups allow you to combine various rules.

Routine: You use routines to implement complex transformation rules yourself. Routines are available as a rule type. There are also routine types that you can use to implement additional transformations.


Replication of datasourcesIn the SAP source system, the DataSource is the BI-relevant metaobject that makes source data available in a flat structure for data transfer into BI. In the source system, a DataSource can have the SAP delivery version (D version: Object type R3TR OSOD) or the active version (A version: Object type R3TR OSOA).

FeaturesDepending on your requirements, you can replicate into the BI system either the entire metadata of an SAP source system (application component hierarchy and DataSources),

The DataSource of an application component in a source system, is an individual DataSources of a source system.

When you create an SAP source system, an automatic replication of the metadata takes place.

Whenever there is a data request, an automatic replication of the DataSource takes place if the DataSource in the source system has changed.

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Data Acqusition