SAP NetWeaver Business Warehouse
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Purpose

The purpose of this page is to clarify the understanding of the system logic and requirements in relation to SAP LT / ODP based real-time replication.

Overview

Architectural Concept

SAP LT Replication Server can replicate data from ABAP and non-ABAP source systems into the Operational Delta Queue of the SLT system. Thus, SLT itself acts as the target of the SLT configurations. Data gets replicated as soon as a subscriber requests the data from a data source from an ODP Context. Several subscribers can use the same ODQ as source. SAP BW can use this scenario with scheduled data transfer from ODQ as of SAP BW 7.30. A setup for real-time data transfer with Data Transfer Processes (DTP) into BW Data Targets and RDA Daemon is possible with SAP BW 7.40 SP5.

Real-time or scheduled replication to SAP BW with SLT (as of SAPKW74005)




New Source System Type ODP-SLT
Benefits

SLT Real-Time push in Operational Delta Queue (ODQ)

Simplified data flow

Direct Update to BW InfoProviders

PSA no longer required

Scheduled or real–time daemon

Consumption of ODQ by multiple subscribers

Automatic change notification for daemon

Delta handling for Non-SAP sources which are supported by SLT

Set up of SLT replication from SAP BW


ODP/SLT Scenario with Subscriber SAP BW


  • Setup with Data Transfer Process into BW Data Targets and RDA Daemon possible with SAP BW 7.4 SP5
  • Non-SAP source system delta handling with SLT

Example: New SLT/ODP scenarios with SAP BW 7.4


  1. Create Open ODS View (Sales Order) with first Associations ( Views for Employees and Departments). Add additional customer InfoObject to experience the BW master data integration. (DIRECT ACCESS)
  2.  Create based on the created Open ODS View a persistency via a generated Field based DataStore Object (FULL data uploads)
  3. Change the data flow and create a RDA data transfer based on a given SLT-ODQ and switch your scenario to (REAL-TIME DELTA uploads)

Technical Requirements

See Technical Requirements for ODP SLT Scenario with SAP BW

Reproduction of simple BW Extractors with SLT's View functionality

View-based SLT delta-transfer technology (with SP06):

Simple BW Extractors can be rebuilt with Views, if the following prerequisites are fulfilled:

  • Views need to be built which need to contain all relevant tables
  • the view relations as well as the primary key of the view need to be designed
  • there must be a hierarchy with one main table
  • only this main table is triggered/recorded (means the line item tables attached to the main table are not triggered)
  • Target is 1 transparent table (there is no data split after SLT transfer e.g. into two or more tables) The capability is shipped as a framework; content is not part of the shipment!

The capability is shipped as a framework; content is not part of the shipment!

Benefits compared to standard BW Extractors:

  • Can go across clients, reducing number of running processes and setup efforts for each client 
  • Enhances tables with delta capabilities, thus streamlines the dataflow from full to delta for transferred data.

Keypoints

  1. BW 7.4 provides major enhancements for Operational Data Provisioning (ODP) and Operational Delta Queue(ODQ) Handling. The ODP Framework supports all kind of Source System types.
  2. Highly efficient compression enables data compression rates up to 90% in the Operational Delta Queue (ODQ) with configurable data retention periods per subscriber/consumer.
  3. Layer Reduction in BW - PSA layer obsolete during Data Acquisition because DTP directly reads from ODQ persistence.
  4. Runtime is reduced by more than 40% (lab results) loading from the Operational Delta Queue in the source system via DTP into a DSO.
  5. Simplified SLT handling for BW targets – SLT Replications addresses ODQ instance from where BW takes the data using DTPs and RDA Daemon.
  6. Delta handling for non-SAP sources, which are supported by SLT.

Authorization

SLT-user requires the profiles SAP_IUUC_REPL_ADMIN and SAP_IUUC_REPL_ADMIN_BW_ODQ. If the user does not have this authorization, the effect might be Timeouts during ODP. 

Transactions

  • LTRC: SAP LT Replication Server Cockpit.
    • Shows overview about available configurations and configuration data.
    • The ODQ-relevant setup in SLT is done here. The ODQ-configuration contains the RFC-connection from source system, the target RFC-connection has to be 'NONE' (as ODQ is in SLT-system).
    • The queue alias defined for the ODQ-configuration in LTRC has to be identical with the one in SAP BW when creating the SLT source system.
  • LTR: Similar to LTRC, only web-based
  • LTRS: Advanced Replication Settings; Here you can define the tables to replicated. 

Tables / Various 

SLT-tables related to ODQ follow the naming convention IUUC_ODQ*:

  • IUUC_ODQ_ALIAS: Mapping of SLT Mass Transfer ID to ODQ-alias
  • IUUC_ODQ_TAB_HIS: Contains all requests from BW to SLT
  • The selection in SLT is saved in 3 tables:
    • IUUC_ODQ_TABLES: Header table for selection
    • IUUC_ODQ_PRJ: Projection fields of request
    • IUUC_ODQ_PARAM: Selection fields from BW. They are only relevant in case of Init. In delta SLT does not consider any selection, ODQ has to take care for this.
  • The master replication job in SLT is called: /1LT/IUC_REP_MSTR . If this job is not running, no data is replicated to ODQ.
  • The writing to ODQ is done via class CL_ODQ_FACADE. For Full/Init the method get_request_writer is used, in case of delta get_queue_writer.
  • SLT-classes for ODQ:
    • CL_IUUC_ODQ_PROVIDER, e.g. method IF_ODQ_QUEUE_MODEL~OPEN_EXTRACTOR
    • CL_IUUC_ODQ_TABLES_ACCESS