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2 SAP AG Neurottstraße Walldorf Germany T +49/18 05/ F +49/18 05/ SAP AG. All rights reserved. No part of this publication may be reproduced or transmitted in any form or for any purpose without the express permission of SAP AG. The information contained herein may be changed without prior notice. Some software products marketed by SAP AG and its distributors contain proprietary software components of other software vendors. Microsoft, Windows, Excel, Outlook, and PowerPoint are registered trademarks of Microsoft Corporation. IBM, DB2, DB2 Universal Database, System i, System i5, System p, System p5, System x, System z, System z10, System z9, z10, z9, iseries, pseries, xseries, zseries, eserver, z/vm, z/os, i5/os, S/390, OS/390, OS/400, AS/400, S/390 Parallel Enterprise Server, PowerVM, Power Architecture, POWER6+, POWER6, POWER5+, POWER5, POWER, OpenPower, PowerPC, BatchPipes, BladeCenter, System Storage, GPFS, HACMP, RETAIN, DB2 Connect, RACF, Redbooks, OS/2, Parallel Sysplex, MVS/ESA, AIX, Intelligent Miner, WebSphere, Netfinity, Tivoli and Informix are trademarks or registered trademarks of IBM Corporation. Linux is the registered trademark of Linus Torvalds in the U.S. and other countries. Adobe, the Adobe logo, Acrobat, PostScript, and Reader are either trademarks or registered trademarks of Adobe Systems Incorporated in the United States and/or other countries. SAP, R/3, xapps, xapp, SAP NetWeaver, Duet, PartnerEdge, ByDesign, SAP Business ByDesign, and other SAP products and services mentioned herein as well as their respective logos are trademarks or registered trademarks of SAP AG in Germany and in several other countries all over the world. All other product and service names mentioned are the trademarks of their respective companies. Data contained in this document serves informational purposes only. National product specifications may vary. These materials are subject to change without notice. These materials are provided by SAP AG and its affiliated companies ("SAP Group") for informational purposes only, without representation or warranty of any kind, and SAP Group shall not be liable for errors or omissions with respect to the materials. The only warranties for SAP Group products and services are those that are set forth in the express warranty statements accompanying such products and services, if any. Nothing herein should be construed as constituting an additional warranty. Disclaimer Some components of this product are based on Java. Any code change in these components may cause unpredictable and severe malfunctions and is therefore expressively prohibited, as is any decompilation of these components. Any Java Source Code delivered with this product is only to be used by SAP s Support Services and may not be modified or altered in any way. Oracle is a registered trademark of Oracle Corporation. UNIX, X/Open, OSF/1, and Motif are registered trademarks of the Open Group. Citrix, ICA, Program Neighborhood, MetaFrame, WinFrame, VideoFrame, and MultiWin are trademarks or registered trademarks of Citrix Systems, Inc. HTML, XML, XHTML and W3C are trademarks or registered trademarks of W3C, World Wide Web Consortium, Massachusetts Institute of Technology.

3 Contents About this Guide... 4 Target scenario... 5 Architecture... 6 Features... 8 Mass data and performances... 8 Limitations... 9 About BI Further reading September,

4 About this Guide SAP BusinessObjects Data Federator (DF) is often proposed as a solution for BusinessObjects Enterprise (BOE) XI 3.1 SP4 reporting; involving mass data from SAP Business Information Warehouse (SAP BW). It is important to fully understand its features and limitations in order to make the best use of it. This document aims to clarify these limitations.. The SAP BusinessObjects Data Federator BW connector allows BOE tools to access SAP BW data in a relational way by bypassing BW MDX and OLAP calculation engines and BOE MDX flattening, thereby saving computation overhead and losing some functionalities. In order to understand what to expect from the DF BW connector, both in performance and features, it is important to understand the overall architecture of the solution. Therefore, this document starts with an architectural overview and then details consequences on performance and features. 4 September, 2011

5 Target scenario Data warehouses can meet the needs of a predictable data environment. But real-time business needs often require you to consolidate information that's scattered across your organization and to do it quickly. SAP BusinessObjects Data Federator software can enable you to leverage your current infrastructure and available data sources to create a unified view of your data sources in a fast, flexible, accessible way. Providing real-time, on-demand access to diverse data sources, the software allows you to quickly introduce new data sources to your business intelligence solutions and adapt to changing data integration requirements. SAP Data Federator is a data mediation solution: it allows to define and to expose a virtual SQL interface federating several data sources without moving data around. For example, the DF BW connector allows leveraging SAP NetWeaver BW as a DF data source, in order to federate data from BW with data from a third-party relational database. In order to do so, BW data are queried by DF in a relational way, thereby avoiding the overhead of the calculation engine (see the section Architecture). However, sometimes customers use DF with BW as a unique data source in order to get better performance with BOE clients (e.g., Web Intelligence) than with BOE 3.1 OLAP universes. September,

6 Architecture Without the SAP Data Federator BW Connector, BOE tools such as Web Intelligence connect to SAP BW trough OLAP Universes where the business objects are defined using MDX (OLAP query language). The SAP Data Federator BW Connector is a SQL connector; with it, tools like Web Intelligence have the option to connect to SAP BW trough Relational Universes where business objects are defined using SQL language. The SAP Data Federator BW connector is providing access to the SAP BW enterprise data warehouse, exposing an easy-to-use well-known query language (SQL), allowing the combination of SAP BW sources with other sources (SAP or non-sap). Figure 1 displays the overall architecture Webi Universe / information engine XML/MDX SQL BEX client OLAP Data Access (ODA) Data Federator Query Server JCO Data Federator Facade Analytical Engine BICS Engine MDX Engine Master Data Serrvice Meta Data Repository Calculation engine Aggregation Engine InfoProvider NW BW Server Figure 1 6 September, 2011

7 Data Federator accesses BW through a specific facade and this facade gets data from the aggregation engine, i.e., under the calculation (OLAP) engine and above the aggregation engine 1. (The facade does not access directly the info providers / physical tables.) It is also important to understand that InfoProviders are exposed to DF through the facade as a set of logical tables in a snowflake schema. DF Query server has to handle the execution of the join relationships of this snowflake2. Here is a summary of what SQL fragments can be executed by BW aggregation engine and what have to be executed by DF Query server: Capability on logical tables of an InfoProvider Join execution SUM, MIN and MAX aggregation AVG, COUNT aggregation Filter Sort SQL functions / expression DF Query Server SQL Engine through the facade BW aggregation engine Partial When execution has to be carried over by DF Query Server, this has an impact of performance because all necessary data have to be retrieved from BW to DF Query Server through the network. Of course, Data Federator execution algorithms try to minimize the amount of data which has to travel through the network, for example by trying to push filters and grouping to the aggregation engine or using semi-join techniques. However, in some cases, the transfer from BW to DF through the network will be a performance bottleneck. 1 The aggregation engine reads from the physical tables of an InfoProvider and provides some database functionalities. 2 a snowflake schema is a logical arrangement of tables such that the entity relationship diagram resembles a snowflake in shape. The snowflake schema is represented by centralized fact tables which are connected to multiple dimensions. September,

8 Features In this section, the main BW features which are supported by the DF BW connector are listed; they can therefore be used as is by BOE clients. BW Feature BOE through Data Federator BW connector Comments InfoProviders supported Partial Supported InfoProviders are InfoCube, Operational DataStore, InfoObject, MultiProvider, HybridProvider, VirtualProvider, InfoSet Cumulative key figure Navigational attributes Security Single Sign-On with Universe Designer (minimal requirement SAP BusinessObjects Enterprise SP3 FP3.1) AVG, COUNT, SUM, MIN, MAX Mass data enabled See next section See next subsection: mass data and performances Multi source enabled This is a feature that Data Federator provides on top of BW. Mass data and performances As explained in the Architecture section, the limited SQL capabilities of the aggregation engine as exposed by the facade sometimes caused the data transfer between BW and the DF Query Server to act as a performance bottleneck. On the other hand, a DF BW connector bypasses the calculation engine, the MDX engine and the BOE MDX flattening, which can enable considerable performance improvement compared to BW access through MDX. So yes, using the DF BW connector will allow you to access mass data with BOE in better condition than from the BOE MDX connector. However, you may not always get performances as good as with BEX using the BICS connector. How a specific Web Intelligence request will perform with a DF BW connector is a case-bycase problem. It requires an analysis of the way the DF Query Server will execute the SQL, how much will be pushed to the aggregation engine and overall of the data volume that will have to be transferred between BW and the DF Query Server. The Bottom Line: Yes, the DF BW connector somewhat enables mass data access with BOE: however, you should not expect the same performance level as with BEX in all cases. 8 September, 2011

9 Limitations As seen in section Architecture, Data Federator accesses BW through a facade which bypasses the OLAP calculation engine. Doing so allows leveraging the Data Federator relational federation capabilities and a faster access for BOE client through a relational universe. However, this has a cost in term of features: BW Feature BEx queries BW variables Restricted key figures Non-cumulative key figures BW Hierarchies Currency and unit conversion Exceptions Conditions Other aggregations (e.g. STD) BOE through Data Federator BW connector Comments BEx queries support require BICS engine. There is no workaround for this limitation. BW variables are calculation engine features. Some variables can be partially simulated with prompt in BOE universe. Restricted key figures are BEx features. However, it can be partially emulated in universe definition with a measure using a CASE statement. Non-cumulative key figures are a calculation engine feature. There is no workaround for this limitation. BW hierarchies are handled by calculation engine. There is no work around available. Currency/unit conversion is a calculation engine feature. It is not automatically handled by DF, however it can be partially simulated with Universe or DF target tables authoring. Exception is a BEx feature. It can be partially simulated by Web Intelligence using alerting (color coding). Condition is a BEx feature. It can be partially simulated by Web Intelligence with filters on measures and Top/Bottom. STD Aggregation is handled by calculation engine. DF does not support STD and compensate. September,

10 About BI 4.0 Data Federator appears in SAP BusinessObjects BI 4.0 only as a backend engine empowering Multi-Source Universe (MSU). In the 4.0 version it is not possible to author target tables as with DF 3.x. The 4.0 the DF BW connector is much the same as the 3.0 version. However, it is mainly aimed at supporting multi-source universe (e.g., BW and a relational data source) and not to allow mass data access on a single BW source (also there is no Data Federator Designer in BI 4.0). In BI 4.0 the recommended access methods for Webi to BW for mass access data is BICS. Other clients such as Analysis OLAP or Analysis Office are also available to access BW with performance. A careful choice of the client based on business needs is recommended. 10 September, 2011

11 Further reading For detail explanations about Data Federator performances please refers to Data Federator Tuning and Performance Guide. September,