What is table partition ?
SAP is using fact table partitioning to improve the performance. you can partition only on 0CALMONTH or 0FISCPER
How would you convert a info package group into a process chain ?
Double Click on the info package grp, click on the 'Process Chain Maint' button and type in the name and description; the individual info packages are inserted automatically.
How do you replace a query result from a master query to a child query ?
If you select characteristic value with replacement path then it used the results from previous query; for ex: let us assume that u have query Q1 which displays the top 10 customers, we have query Q2 which gets the top 10 customers for info object 0customer with as a variable with replacement path and display detailed report on the customers list passed from Q1.
What is modeling ?
It is an art of designing the data base. The design of DB depends on the schema and the schema is defined as representation of tables and their relationships.
What is an info cube ?
Info cube is structured as star schema (extended) where a fact table is surrounded by different dim table that are linked with DIM-ids. And the data wise, you will have aggregated data in the cubes.
What is extended star schema ?
- In Extended Star Schema, under the BW star schema model, the dimension table does not contain master data. But it is stored externally in the master data tables (texts, attributes, hierarchies).
- The characteristic in the dimensional table points to the relevant master data by the use of SID table. The SID table points to characteristics attribute texts and hierarchies.
- This multistep navigational task adds extra overhead when executing a query. However the benefit of this model is that all fact tables (info cubes) share common master data tables between several info cubes.
- Moreover the SID table concept allows users to implement multi languages and multi hierarchy OLAP environments. And also it supports slowly changing dimension.
- delete a BEx query that is in Production system through request.
- A) Using the RSZDELETE transaction
How would you optimize the dimensions ?
We should define as many dimensions as possible and we have to take care that no single dimension crosses more than 20% of the fact table size.
What are Conversion Routines for units and currencies in the update rule ?
Using this option we can write ABAP code for Units / Currencies conversion. If we enable this flag then unit of Key Figure appears in the ABAP code as an additional parameter. For example, we can convert units in Pounds to Kilos.
Can an Info Object be an Info Provider, how and why ?
Yes, when we want to report on Characteristics or Master Data. We have to right click on the Info Area and select 'Insert characteristic as data target'. For example, we can make 0CUSTOMER as an Info Provider and report on it.
What is Open Hub Service ?
The Open Hub Service enables us to distribute data from an SAP BW system into external Data Marts, analytical applications, and other applications. We can ensure controlled distribution using several systems. The central object for exporting data is the Info Spoke. We can define the source and the target object for the data. BW becomes a hub of an enterprise data warehouse. The distribution of data becomes clear through central monitoring from the distribution status in the BW system.
How do you transform Open Hub Data ?
Using BADI we can transform Open Hub Data according to the destination requirement.
What is ODS ?
Operational Data Source is used for detailed storage of data. We can overwrite data in the ODS. The data is stored in transparent tables.
What are BW Statistics and what is its use ?
They are group of Business Content Info Cubes which are used to measure performance for Query and Load Monitoring. It also shows the usage of aggregates, OLAP and Warehouse management.
What are the steps to extract data from R/3 ?
- Maintain Communication Structure and Transfer rules
What are the delta options available when you load from flat file ?
- The 3 options for Delta Management with Flat Files:
- New Status for Changed records (ODS Object only)
- Additive Delta (ODS Object & Info Cube)
What are the extractor types ?
- BW Content FI, HR, CO, SAP CRM, LO Cockpit
- Customer-Generated Extractors
- Cross Application (Generic Extractors)
- DB View, InfoSet, Function Module
What are the steps involved in LO Extraction ?
The steps are:
- RSA5 Select the Data Sources
- LBWE Maintain Data Sources and Activate Extract Structures
- RSA3 Check extraction and the data in Setup tables
- LBWQ Check the extraction queue
- LBWF Log for LO Extract Structures
- RSA7 BW Delta Queue Monitor
How to create a connection with LIS Info Structures ?
LBW0 Connecting LIS Info Structures to BW
What is the difference between ODS and Info Cube and Multi Provider ?
- ODS: Provides granular data, allows overwrite and data is in transparent tables, ideal for drill down and RRI.
- CUBE: Follows the star schema, we can only append data, ideal for primary reporting.
- Multi Provider: Does not have physical data. It allows to access data from different Info Providers (Cube, ODS, Info Object). It is also preferred for reporting.
What are Start routines, Transfer routines and Update routines ?
- Start Routines: The start routine is run for each Data Package after the data has been written to the PSA and before the transfer rules have been executed. It allows complex computations for a key figure or a characteristic. It has no return value. Its purpose is to execute preliminary calculations and to store them in global Data Structures. This structure or table can be accessed in the other routines. The entire Data Package in the transfer structure format is used as a parameter for the routine.
- Transfer / Update Routines: They are defined at the Info Object level. It is like the Start Routine. It is independent of the Data Source. We can use this to define Global Data and Global Checks.
What is the difference between start routine and update routine, when, how and why are they called ?
Start routine can be used to access Info Package while update routines are used while updating the Data Targets.
What is Star Schema ?
- In Star Schema model, Fact table is surrounded by dimensional tables. Fact table is usually very large, that means it contains millions to billions of records. On the other hand dimensional tables are very small. Hence they contain a few thousands to few million records. In practice, Fact table holds transactional data and dimensional table holds master data.
- The dimensional tables are specific to a fact table. This means that dimensional tables are not shared to across other fact tables. When other fact table such as a product needs the same product dimension data another dimension table that is specific to a new fact table is needed.
- This situation creates data management problems such as master data redundancy because the very same product is duplicated in several dimensional tables instead of sharing from one single master data table. This problem can be solved in extended star schema.
What is slowly changing dimension ?
Dimensions those changes with time are called slowly changing dimension.
What is fact table ?
Fact table is the collection if facts and relations that means foreign keys with the dimension. Actually fact table holds transactional data.
What is dimension table ?
Dimension table is a collection of logically related descriptive attributes that means characteristics.
How many tables does info cube contain ?
Actually info cube contains two tables. E table and F (fact) table.
What is the maximum no. of dimensions in info cube ?
16 ( 3 are sap defines and 13 are customer defined )
What are the minimum no of dimensions in info cube ?
4 ( 3 Sap defined and 1 customer defined ) .
What are the 3SAP defined dimensions ?
- The 3 SAP defined dimensions are ...
- 1. Data packet dimension (P)...it contains 3characteristics.a) request Id (b) Record type (c) Change run id
- 2. Time dimension (T)..it contains time characteristics such as 0calmonth, 0calday etc
- 3. Unit Dimension (U).it contains basically amount and quantity related units.
What is the model of the info cube ?
Info cube model is extended star schema.
What are the data types for the characteristic info object ?
There are 4types:
- CHAR
- NUMC
- DATS
- TIMS
How you'll write date in BW ?
YYYYMMDD
What is the difference between open sql & native sql ?
- Open SQL allows you to access all database tables known to the SAP system, regardless of the database manufacturer. Sometimes, however, we may want to use database-specific SQL statements called Native SQL in your ABAP/4 program.
- To avoid incompatibilities between different database tables and also to make ABAP/4 programs independent of the database system in use, SAP has created a set of separate SQL statements called Open SQL. Open SQL contains a subset of standard SQL statements as well as some enhancements which are specific to SAP.
- A database interface translates SAP's Open SQL statements into SQL commands specific to the database in use. Native SQL statements access the database directly.
What is Primary key, foreign key ? what is primary index? secondary index ?
Primary index: the primary index contains key fields of a table and a pointer to non-key fields of the table. The primary index is created automatically when a table is created in database and moreover you can further define reference to the primary index which are known as Secondary index.
