An aggregate is a subset of an InfoCube. The objective when using aggregates is to reduce I/O volume. The BW OLAP processor selects an appropriate aggregate during a query run or a navigation step. If no appropriate aggregate exists, the BW OLAP processor retrieves data from the original InfoCube instead.
Aggregate rollup is a procedure to update aggregates with new data loads.
Application components are used to organize InfoSources. They are similar to the InfoAreas used with InfoCubes. The maximum number of characters allowed for the technical name is 32.
An authorization defines what a user can do, and to which SAP objects. For example, a user with an authorization can display and execute, but not change, a query. Authorizations are defined using authorization objects.
An authorization object is used to define user authorizations. It has fields with values to specify authorized activities, such as display and execution, on authorized business objects, such as queries. The maximum number of characters allowed for the technical name is 10.
An authorization profile is made up of multiple authorizations. The maximum number of characters allowed for the technical name is 10.
A bitmap index uses maps of bits to locate records in a table. Bitmap indices are very effective for Boolean operations of the WHERE clause of a SELECT statement. When the cardinality of a column is low, a bitmap index size will be small, thereby reducing I/O volume.
Business Content is a complete set of BW objects developed by SAP to support the OLAP tasks. It contains roles, workbooks, queries, InfoCubes, key figures, characteristics, update rules, InfoSources, and extractors for SAP R/3, and other mySAP solutions.
BW is a data warehousing solution from SAP.
BW Monitor displays data loading status and provides assistance in troubleshooting if errors occur.
BW Scheduler specifies when to load data. It is based on the same techniques used for scheduling R/3 background jobs.
BW Statistics is a tool for recording and reporting system activity and performance information.
Change run is a procedure used to activate characteristic data changes.
Characteristics are descriptions of key figures, such as Customer ID, Material Number, Sales Representative ID, Unit of Measure, and Transaction Date. The maximum number of characters allowed for the technical name is 9.
A client is a subset of data in an SAP system. Data shared by all clients is called client-independent data, as compared with client-dependent data. When logging on to an SAP system, a user must specify which client to use. Once in the system, the user has access to both client-dependent data and client-independent data.
The communication structure is the structure underlying the InfoSource.
A compound attribute differentiates a characteristic to make the characteristic uniquely identifiable. For example, if the same characteristic data from different source systems mean different things, then we can add the compound attribute 0SOURSYSTEM (source system ID) to the characteristic; 0SOURSYSTEM is provided with the Business Content.
Data packet size
For the same amount of data, the data packet size determines how work processes will be used in data loading. The smaller the data packet size, the more work processes needed.
Data Warehouse is a dedicated reporting and analysis environment based on the star schema database design technique and requiring special attention to the data ETTL process.
A DataSource is not only a structure in which source system fields are logically grouped together, but also an object that contains ETTL-related information. Four types of DataSources exist:
If the source system is R/3, replicating DataSources from a source system will create identical DataSource structures in the BW system. The maximum number of characters allowed for a DataSource's technical name is 32.
The Delta update option in the InfoPackage definition requests BW to load only the data that have been accumulated since the last update. Before a delta update occurs, the delta process must be initialized.
A development class is a group of objects that are logically related.
A display attribute provides supplemental information to a characteristic.
Drill-down is a user navigation step intended to get further detailed information.
ETTL, one of the most challenging tasks in building a data warehouse, is the process of extracting, transforming, transferring, and loading data correctly and quickly.
A free characteristic is a characteristic in a query used for drill-downs. It is not displayed in the initial result of a query run.
The Full update option in the InfoPackage definition requests BW to load all data that meet the selection criteria specified via the Select data tab.
Generic data extraction
Generic data extraction is a function in Business Content that allows us to create DataSources based on database views or InfoSet queries. InfoSet is similar to a view but allows outer joins between tables.
Granularity describes the level of detail in a data warehouse. It is determined by business requirements and technology capabilities.
IDoc (Intermediate Document) is used in SAP to transfer data between two systems. It is a specific instance of a data structure called the IDoc Type, whose processing logic is defined in the IDoc Interface.
An index is a technique used to locate needed records in a database table quickly. BW uses two types of indices: B-tree indices for regular database tables and bitmap indices for fact tables and aggregate tables.
InfoAreas are used to organize InfoCubes and InfoObjects. Each InfoCube is assigned to an InfoArea. Through an InfoObject Catalog, each InfoObject is assigned to an InfoArea as well. The maximum number of characters allowed for the technical name is 30.
An InfoCube is a fact table and its associated dimension tables in the star schema. The maximum number of characters allowed for the technical name is 30.
InfoCube compression is a procedure used to aggregate multiple data loads at the request level.
In BW, key figures and characteristics are collectively called InfoObjects.
InfoObject Catalogs organize InfoObjects. Two types of InfoObject Catalogs exist: one for characteristics, and one for key figures. The maximum number of characters allowed for the technical name is 30.
An InfoPackage specifies when and how to load data from a given source system. BW generates a 30-digit code starting with ZPAK as an InfoPackage's technical name.
An InfoSource is a structure in which InfoObjects are logically grouped together. InfoCubes and characteristics interact with InfoSources to get source system data. The maximum number of characters allowed for the technical name is 32.
Key figures are numeric values or quantities, such as Per Unit Sales Price, Quantity Sold, and Sales Revenue. The maximum number of characters allowed for the technical name is 9.
Line item dimension
A line item dimension in a fact table connects directly with the SID table of its sole characteristic.
A logical system is the name of a client in an SAP system.
A multi-cube is a union of basic cubes. The multi-cube itself does not contain any data; rather, data reside in the basic cubes. To a user, the multi-cube is similar to a basic cube. When creating a query, the user can select characteristics and key figures from different basic cubes.
A navigational attribute indicates a characteristic-to-characteristic relationship between two characteristics. It provides supplemental information about a characteristic and enables navigation from characteristic to characteristic during a query.
A number range is a range of numbers that resides in application server memory for quick number assignments.
ODS is a BW architectural component located between PSA and InfoCubes that allows BEx reporting. It is not based on the star schema and is used primarily for detail reporting, rather than for dimensional analysis. ODS objects do not aggregate data as InfoCubes do. Instead, data are loaded into an ODS object by inserting new records, updating existing records, or deleting old records, as specified by the 0RECORDMODE value.
A parallel query uses multiple database processes, when available, to execute a query.
A partition is a piece of physical storage for database tables and indices. If the needed data reside in one or a few partitions, then only those partitions will be selected and examined by a SQL statement, thereby significantly reducing I/O volume.
Profile Generator is a tool used to create authorization profiles.
PSA is a data staging area in BW. It allows us to check data in an intermediate location, before the data are sent to its destinations in BW.
A BW query is a selection of characteristics and key figures for the analysis of the data in an InfoCube. A query refers to only one InfoCube, and its result is presented in a BEx Excel sheet. The maximum number of characters allowed for the technical name is 30.
Read mode for a query determines the size and frequency of data retrievals from database: all data at once, as needed per navigation step, or as needed per hierarchy node.
Reconstruct is a procedure used to restore load requests from PSA.
A request is a data load request from BW Scheduler. Each time that BW Scheduler loads data into an InfoCube, a unique request ID is created in the data packet dimension table of the InfoCube.
RFC (Remote Function Call) is a call to a function module in a system different from the caller's – usually another SAP system on the local network.
In Profile Generator, an authorization profile corresponds to a role. A user assigned to that role also has the corresponding authorization profile. A user can be assigned to multiple roles. The maximum number of characters allowed for the technical name is 30.
SID (Surrogate-ID) translates a potentially long key for an InfoObject into a short four-byte integer, which saves I/O and memory during OLAP.
A source system is a protocol that BW uses to find and extract data. When the source system is a non-SAP system, such as a flat file or a third-party tool, the maximum number of characters allowed for the technical name is 10. When the source system is an SAP system, either R/3 or BW, the technical name matches the logical system name. The maximum number of characters allowed for the technical name is 32.
A star schema is a technique used in the data warehouse database design to help data retrieval for online analytical processing.
For a SQL statement, many execution plans are possible. The database optimizer generates the most efficient execution plan based on either the heuristic ranking of available execution plans or the cost calculation of available execution plans. Statistics is the information that the cost-based optimizer uses to calculate the cost of available execution plans and select the most appropriate one for execution. BW uses the cost-base optimizer for Oracle databases.
System Administration Assistant
System Administration Assistant is a collection of tools used to monitor and analyze general system operation conditions.
The system landscape specifies the role of each system and the paths used in transporting objects among the various systems.
Time-dependent entire hierarchy
A time-dependent entire hierarchy is a time-dependent hierarchy whose nodes and leaves are not time-dependent.
Time-dependent hierarchy structure
A time-dependent hierarchy structure consists of nodes or leaves that are time-dependent, but the hierarchy itself is not time-dependent.
Transfer rules specify how DataSource fields are mapped to InfoSource InfoObjects.
A transfer structure maps DataSource fields to InfoSource InfoObjects.
An update rule specifies how data will be updated into their targets. The data target can be an InfoCube or an ODS object. If the update rule is applied to data from an InfoSource, the update rule's technical name will match the InfoSource's technical name. If the update rule is applied to data from an ODS object, the update rule's technical name will match the ODS object's technical name prefixed with number 8.
A variable is a query parameter. It gets its value from user input or takes a default value set by the variable creator.
A BW workbook is an Excel file with a BEx query result saved in BDS. BW assigns a 25-digit ID to each workbook. Users need merely name a workbook's title.
Part I. Guided Tours
Business Scenario and SAP BW
Creating an InfoCube
Loading Data into the InfoCube
Checking Data Quality
Creating Queries and Workbooks
Managing User Authorization
Part II. Advanced Topics
Aggregates and Multi-Cubes
Operational Data Store (ODS)
Generic R/3 Data Extraction
Appendix A. BW Implementation Methodology
Appendix B. SAP Basis Overview
Appendix C. Glossary
Appendix D. Bibliography