Info Area: - Infoarea is a folder which is used to segregate the project.
Source system: - The system from which we extract the data to BIW system is called as Source System.
Info source: - Info source is defined as a communication structure grouping of logically related info objects in which format data has to be loaded to BIW system. Ex: water tank – Pipe – storage area.
Data source: - Data source defines transfer structure. Grouping of logically related fields in which format data has to be extracted from the source machine.
o Data source is specific to source system.
o If it is Flat file Extraction source system itself is the data source.
Transfer Rules: - transfer rules defines how data has to be transformed from Data source to Info source.
PSA (Persistent storage area): - Data coming from source system has been staged BIW at PSA has 2 dimension tables
o Any error comes, updation will Stop at PSA table, rectify the data in PSA and update into the target.
Info Package: - Info package is a scheduler which defines when load has to be triggered.
Info Cube: - Info cube is an info provider as well as Data Target. Objects which send data from Info cube are called Info provider.
Types of Cube: -
o Info cubes are categorized into 2 categories.
o Standard Info Cube
o Real Time Info Cube
Standard Info Cube: - In a standard info cube we cannot load data Manually.(Planning is not possible)
Real Time Info Cube: - in a Real Time Info Cube we can load data manually. (Planning is allowed)
DSO (Data Store Object): - If the Data source is not maintaining the reference in the form of Images, Load data to DSO. DSO will maintain the images from DSO load data to Info Cube.
o New Image “ N ”
o Before Image “ X ”
o After Image “ _ ” (Blank, No symbol)
o New Image:- Any record which enters the DSO for the 1st time will be marked as “N” (New Image)
o Before Image: - whenever we load modified record to DSO, it takes as 2 records.
When we create DSO, system generates 3 tables in the DB
• New Data Table
• Active Data Table
• Change Log Table
o Whenever we load data to DSO, Data enters New Data Table First.
o When we activate the data in DSO, data moves from New Data Table to Active Data Table and Change Log Table.
o When we load data to Info Cube from DSO with Full Update data comes from Active Data Table of DSO.
o With Delta update Data comes from Change Log Table of DSO.
o Change Log Table will maintain Images.
o Data in Active Table Overwrites.
Advantages of DSO
o To maintain Images
o To utilize overwrite functionality
o Acts as backup
o Detailed level of analyzing
o Reconciliation (To check data coming from Source is same or not)
Types of DSO
o Standard DSO 1. NDT, 2. ADT, 3. CLT.
o Direct update DSO – we can update data manually & it has only one table that is Active Data Table.
o Write Optimized DSO – when ever our update has to stop at DSO level we use write optimized DSO. W.O. DSO has only one table – Active data table.
Multiprovider: - Multiprovider is a info provider, but not a data target.
o In DB terminology Multiproviders are nothing but a View.
o Multiprovider will not hold data physically.
o When ever we want Query by combining data from 2 or more info providers we can use Multiproviders.
o Using Multiproviders we can combine
• Info objects (P Table)
• Info cubes (F Table)
• DSO (Active Data Table)
• Info Set
o When ever we want to create a Multiprovider, at least there should be one common Info object available in the Info provider. Which we are combining and that Info object should be a part of Primary key.
o Once we close the query there is no physical data in the multiprovider
o When multiprovider is created by default it takes a technical object called as Zero info providers.
o Using zero info providers we can restrict the output of the query with respect to a particular info provider.
o Using multiprovider it is improves DB performance and degrades query performance.
Infoset: - Infoset is an info provider but not a data target.
o Infoset will not hold data physically.
o When ever we want a query by combining a data from 2 or more info providers we use Infoset.
o By using Infoset we can combine
• Info objects
• DSO
• Info cubes (only in version 7)
o In DB terminology infosets are nothing but Joints
2 types of joints in Infoset
o Inner Join
o Left Outer Join
o Advantages of Infoset
• Slow moving analysis
• Slow moving analysis is possible only when it is Left outer join and when Info object is left
• Improves DB performance and degrades query performance
• Maximum of 2 cubes can be used in Infoset, cubes cannot be left
Aggregates: - aggregates are the smaller Cubes, which are built on the main cube in order to improve query performance.
o Aggregates are specific to a character; by default it takes all the key figures of the main Cube.
o Whenever we execute a query the processor will search for a suitable aggregate. If found it fetches data from the aggregate. If not it fetches data from the main Cube.
o Initial Fill: - After creating the aggregates, what ever the Data that we load from the main cube to the aggregates for the 1st time is called initial fill.
o Using aggregated the retrieval rate will be faster.
o OLAP time reduced and DB time.
o Rollup: - After the initial fill what all the data that we load to the main cube has to be Roll Back to aggregates.
o If we don’t do the Rollup the new request will not be available in the aggregates.
o Using aggregates we can increase the query performance & degrades DB performance.
o If DB time is greater than 30% of the time and aggregates ratio should be faster than 10%
o Agg = no of records selected / no of records transferred
Indexes: - Arranging the records in DB with respect to some pointers.
o 2 types of Indexes: -
o 1. Primary Indexes, 2. Secondary Indexes
Bitmap B-Tree (Binary Tree)
Pointers will be in 0’s & 1’s Parent and child relation, for every search it reduces 50% of the properties
P
LC RC
o Using Indexes the retrieval rate will be faster.
o Indexes are created on fact table
o The number of Indexes created on Face table will depend on number of dimensions in cube.
o Before loading data into cube delete index and create indexes after loading.
Line Item Dimension: - when we assign one character to one dimension, will make determine as Line Item Dimension. When we make it as Line Item Dimension there is no extra Dimension table strength away like from SID table to fact table. Using LID improves load performance, DB performance & query performance.
Process Chain: - Group of process associated in the form of a chain in order to automate them is called process chain.
o Process: - Process defines what exactly we are performing.
o Variant: - Variant defines on what object process has to be performed, every process is associated with variant.
o Error Handling in Process chain: - 1. Load Error, 2. Other than Load Error
o If we get load error, it should be rectified manually.
o Error handling should be maintained in log view only.
o Start the chain manually when stopped.
o Other than load error is due to Lock issue for this wait for some time and reload.
Thursday, July 7, 2011
SAP imp Q
Modeling and Performance
1. When should a DSO be used?
a) When Data needs to be overwritten.
b) When highly granular data is required in reports
c) All of the above. Ans : c
2. Can data be edited in PSA when the request is available in the Data Target?
a) Yes
b) No Ans : b
3. Can a request be reconstructed when there is no PSA?
a) No
b) Yes Ans : a
4. When can we have a Line Item Dimension?
a) When we have multiple Line Items
b) When we have a Single Characteristic in a Dimension
c) When we have less number of Characteristics in a Dimension. Ans : b
5. How do we decide on the Characteristics to be included in a Dimension?
a) When the fields (InfoObjects) have m: n relationship.
b) When the fields (InfoObjects) have 1: m relationship.
c) When the fields (InfoObjects) have m: 1 relationship. Ans : a
6. Criteria for selecting PSA and IDOC methods for Data Transfer
a) Load performance.
b) Query performance.
c) Volume of Data. Ans : c
7. All InfoProviders physically hold data
a) True
b) False Ans : b
8. When can we use InfoSets?
a) When Union is required.
b) When Joins are required.
c) All of the above Ans : b
9. Can InfoCubes be included in InfoSets in BI7?
a) No
b) Yes Ans : b
10. What needs to be done to make Attributes Navigable in Queries?
a) Exclude them from the Cube
b) Include them in the Cube
c) Nothing needs to be done. Ans : b
11. Can Queries be used after changes are made to the InfoProvider?
a) Yes
b) No
c) Maybe Ans : a
12. What needs to be done to make the queries work after changes are made to an InfoProvider?
a) Delete and re-create the queries.
b) Re-Generate the queries.
c) Nothing can be done. Ans : b
13. Can a single InfoSource be used to load Data to different InfoProviders?
a) Yes
b) No Ans : a
14. What are Aggregates?
a) Subset of an InfoCube.
b) Outset of a Cube.
c) None of the above. Ans : a
15. Definition of the Cube Dimensions with Master Data Tables can be checked from TCodes
a) LISTCUBE.
b) RSRV.
c) LISTSCHEMA.
d) All of the above. Ans : c
16. Pre-Configuring of ID’s like SID’s, DIM ID’s etc is called
a) Caching.
b) Blobbing.
c) Number Range Buffering.
d) None of the above. Ans : c
17. Application Component Hierarchies can be made available in BW by
a) Importing them in BW.
b) Transferring from SAP R/3.
c) Replicating in BW. Ans : b
18. Post Processing of DataSources is done in
a) RSA3
b) RSA4
c) RSA5
d) RSA6
e) None of the above. Ans : d
19. Testing the Extraction is done by
a) Running a Data Load.
b) Do an Extraction Check in SAP R/3.
c) Running a Query.
d) None of the above. Ans : b
20. How to check the Indices in a Cube?
a) InfoCubeMangePerformance
b) RSRT.
c) All of the above. Ans : c
FAQ in SAP Business Information Warehouse (a part SAP Netweaver)
1. What is table partition?
By using partitioning you can split up the whole dataset for an InfoCube into several, smaller, physically independent and redundancy-free units. Thanks to this separation, performance is increased when reporting, or also when deleting data from the InfoCube.
You can only partition a dataset using one of the two partitioning criteria ‘calendar month’ (0CALMONTH) or ‘fiscal year/period (0FISCPER). At least one of the two InfoObjects must be contained in the InfoCube.
2. What are the options available in transfer rule and when ABAP code is recquired during the transfer rule what important variables you can use?
Assign info object, Assign a Constant , ABAP routine or a Formula
3. How would you optimize the dimensions?
Use as many as possible for performance improvement; Ex: Assume that u have 100 products and 200 customers; if you make one dimension for both ,the size of the dimension will be 20000; if you make individual dimensions then the total number of rows will be 300. Even if you put more than one characterstic per dimension, do the math considering worst case senerio and decide which characterstics may be combined in a dimension.
4. What are the conversion routines for units and currencies in the update rule?
Use
Currency translation during the transformation enables you to convert data records from the source currency into a currency of the target of the transformation.
Currency translation in the transformation is generally performed using previously defined translation types. For more information, see Currency Translation Types.
Where required, you can perform currency translation with user-defined subprograms (formulas and routines). It is not currently possible to execute currency translation for DataStore objects using predefined translation types. You have to use routines instead.
Depending on the type of currency, there are two different types of key figures:
...
1. Key figures with a fixed currency (for example, DEM, USD)
With a fixed currency, the currency is fixed for the amount. The key figure refers specifically to the currency (for example DM, US$), so the currency does not have to be entered again in the data record.
2. Key figures with a variable currency (for example, foreign currency).
With a variable currency, the currency is determined by an InfoObject, (ODOC_CURRCY) for example.
For more information, see Creating InfoObjects: Key Figures.
Features
Transformations can be performed for key figures in two ways:
...
1. Every key figure in an InfoCube (target key figure) has a corresponding key figure in the source (source key figure). No currency translation takes place.
2. There is no corresponding source key figure in the InfoSource for the target key figure in the InfoCube.
a. You can assign a source key figure of the same type to the target key figure (sales revenue instead of sales quantity revenue, for example).
§ If the currencies of both of the key figures are the same, no currency translation can take place.
§ If the currencies are different, a translation can take place either using a currency translation type or by simply assigning a currency.
The following table provides an overview of possible combinations where the currency is not the same in the source and target key figures:
Source key figure currency Target key figure currency Currency translation (CT)
fixed variable No CT
fixed fixed CT
variable fixed CT
variable variable CT or assignment possible
b. If there is no corresponding source key figure of the same type, you have to fill the key figure of the target using a routine.
§ If the currency of the target key figure is fixed, currency translation is not performed. This means that if translation is required, you have to execute it in a routine.
§ If the currency of the target key figure is variable, you also have to assign a variable source currency to the routine. You can use input help to select a currency from the variable currencies that exist for the target. You have two options:
• You can select a variable currency and assign it.
• You can select a currency translation type and a currency into which you wish to translate (‘to’ currency).
By default, the ‘to’ currency is the target currency if it is included in the target.
Creating a routine for currency translation:
If you want to translate currencies during the transformation but currency translation is not available for one of the reasons stated above, you can create a routine. In transformation rule definition, choose Routine with Unit. You get an additional return parameter UNIT in the routine editor and the target currency is determined using the value of this parameter.
5. Can you make an infoobject as info provider and why?
Yes, we can make info object as a info provider. If "CNO"
is one of your info object for characterstics, select that
and right click on that and select the option as " Insert
the characterstic as Data Target". Now your info object
will become your info provider.
Use: We can do Master Data Reporting? with this procedure.
6. What are the steps to unload non cumulative cubes?
1. Initialize openig balance in R/3(S278)
2. Activate extract structure MC03BF0 for data source 2LIS_03_BF
3. setup historical material docus in R/3.
4. load opening balance using data source 2LIS_40_s278
5. load historical movements and compress without marker update.
6. setup V3 Update
7. load deltas using 2LIS_03_BF
7. Give step to step approach to archiving cubex.
1. double click on the cube (or right click and select change)
2. Extras -> Select archival
3. Choose fields for selection(like 0CALDAY, 0CUSTOMER..etc)
4. Define the file structure(max file size and max no of data objects)
5. Select the folder(logical file name)
6. Select the delete options (not scheduled, start automatically or after event)
7. activate the cube.
8. cube is ready for archival.
8. What are the load process and post processing.
Info packake, Read PSA and update data target, Save Hierarchy, Update ODS data object, Data export(open hub), deleteoverlapping requests.
9. What are the data target administration task
delete index, generate index, construct database statistics, initial fill of new aggregates, roll up of filled aggregates, compression of the infocube,activate ODS, complete deletion of data target.
10. What are the parallel process that could have locking problems
heirachy attribute change run
2. loading master data from same infoobject; for ex: avoid master data from different source systems at the same time.
3. rolling up for the same info cube.
4. selecting deletion of info cube/ ODS and parallel loading.
5. activation or delection of ODS object when loading parallel.
11. 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 descrition ; the individual info packages are inserted automatically.
12. How do you transoform Open Hub Data?
In BI7 environment , we can create Open Hub followed by Transformation. At the moment you pick up the Data Source for full update or delta update ,we can able to transform the open Hub data into a flat file(at workstation or Application Server) or into a Open Hub Table. DTP is used to accomplish the data Transfer.
13. What are the data loading tuning one can do?
16. What are the reporting performances one can do?
A : Aggregates, Change the read mode, Pre-calculate data etc
17. What are the data loading tuning one can do
A : Proptionately partition the request with data.
18. What is ODS
A : Most important Data staging structure available in BW
19. What is the use of BW Statistics
A : Provides the statistics information(Performance, response time, load time etc) of all the available objects in BW.
20. What are the options when defining aggregates
A : Please see help documentation there are lot of options
14. What is ODS?
To indicate it's location in the DWH lifecycle, let me tell you the data flow right from being picked up from your source systems till you have your corporate data in form of reports, dashboards & Scorecards.
Source Systems feed data to a intermediate db (called as Staging/Staging area). The data which is here is ready to be fed to a new DB (Operational Data Store). THe purpose of doing this is to allow for reporting on your OLTP meaning just reporting on your Source systems. This can be for adhoc reporting for a shorter periods of time (typically for 2-3 months or 1 quarter).
ODS now has the data from all of your Source Systems. This db acts as a source to your Data warehouse. ETL activities are performed on the ODS and the transformed data in loaded into your enterprise DWH.
It is often reffered to as an interim area for the warehouse.
It stores the current up-to-date cleansed information about the transactions(OLAP) and is available for simple quering.
It can staore upto a maximum of 90 days data.
15. What is the use of BW Statistics?
16. What are the options when definging aggregates?
While creating aggregates
- Contect menu of Data target (Infocube)
- Choose option maintain aggregates
- The system proposes the aggregates
- You can also create them manually
- System proposes the aggregates based on the statistics or on the queries executed with the specific period being mentioned.
- Aggregates have to be saved, activated and filled.
First of all identify which dimensions are really used in queries. based on that the necessary proposed aggregates need to be activated. Not all the proposed ones !!
17. How will you debug errors with SAP GUI (like Active X error etc)
Run Bex analyzer -> Business Explorer menu item -> Installation check; this shows an excel sheetwith a start button; click on it; this verifies the GUI installation ;if u find any errors either reinstallor fix it.
18. When you write user exit for variables what does I_Step do?
I_Step is used in ABAP code as a conditional check.
19. How do you replace a query result from a master query to a child query?
Using Result set Query.It is a nested query where result of first query used as entry values of second query.
20. How do you define exception reporting in the background?
21. What kind of tools are available to monitor the overall Query Performance?
22. What can I do if the database proportion is high for all queries?
23. How to call a BW Query from an ABAP program?
24. What are the extractor types?
If you want to load data from r/3 to bw system, you have to perform data extractions.The extractions are of two types.
Application
Cross Application
In this if you want to load standard data, then you go for LO
if it is customized, you go for Generic extractions, or COPA if it is related to finance.
You transfer data from r/3 and replicate those into BW.
25. What are the steps to extract data from R/3?
26. What are the steps to configure third party (BAPI) tools?
To extract the data from 3rd party system.
27. What are the delta options available when you load from flat file?
full update
delta update
28. What are the table filled when you select ABAP?
29. What are the steps to create classes in SAP-BW
30. How do you convert from LIS to LO extraction?
Maintain extract structure
2) maintain datasource
3)replicate datasource in BW
4)assign infource
5)maintain comm struct
6)maintain IC, UR
7)extract structure active and LIS update off
8)upload the open delta queue (from LIS)
9)empty setup tables
10)setup v3 update
11)initialize
12)IP
31. How do you keep your self-updated on major SAP Develppments, Give an analytical example.
6. WHAT ARE THE DIFFERENT VARIABLES USED IN BEX?
Variable with default entry
Replacement path
SAP exit
Customer exit
Authorization
What is table partition?
A: 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?
A: Double Click on the info package grp, click on the ‘Process Chain Maint’ button and type in the name and descrition ; the individual info packages are inserted automatically.
How do you replace a query result from a master query to a child query?
A: If you select characterstic value with replacement path then it used the results from previuos query; for ex: let us assume that u have query Q1 which displaysthe top 10 customers, we have query Q2 which gets the top 10 customers for info object 0customer with as a vairable 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 InfoObject be an InfoProvider, how and why?
• Yes, when we want to report on Characteristics or Master Data. We have to right click on the InfoArea and select “Insert characteristic as data target”. For example, we can make 0CUSTOMER as an InfoProvider 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 InfoSpoke. 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 DataSource 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 InfoCubes 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?
• Replicate DataSources
• Assign InfoSources
• Maintain Communication Structure and Transfer rules
• Create and InfoPackage
• Load Data
What are the delta options available when you load from flat file?
• The 3 options for Delta Management with Flat Files:
o Full Upload
o New Status for Changed records (ODS Object only)
o Additive Delta (ODS Object & InfoCube)
What are the extractor types?
• Application Specific
o BW Content FI, HR, CO, SAP CRM, LO Cockpit
o Customer-Generated Extractors
LIS, FI-SL, CO-PA
• Cross Application (Generic Extractors)
o DB View, InfoSet, Function Module
What are the steps involved in LO Extraction?
• The steps are:
o RSA5 Select the DataSources
o LBWE Maintain DataSources and Activate Extract Structures
o LBWG Delete Setup Tables
o 0LI*BW Setup tables
o RSA3 Check extraction and the data in Setup tables
o LBWQ Check the extraction queue
o LBWF Log for LO Extract Structures
o RSA7 BW Delta Queue Monitor
How to create a connection with LIS InfoStructures?
• LBW0 Connecting LIS InfoStructures to BW
What is the difference between ODS and InfoCube and MultiProvider?
• ODS: Provides granular data, allows overwrite and data is in transparent tables, ideal for drilldown and RRI.
• CUBE: Follows the star schema, we can only append data, ideal for primary reporting.
• MultiProvider: Does not have physical data. It allows to access data from different InfoProviders (Cube, ODS, InfoObject). It is also preferred for reporting.
What are Start routines, Transfer routines and Update routines?
• Start Routines: The start routine is run for each DataPackage 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 DataStructures. This structure or table can be accessed in the other routines. The entire DataPackage in the transfer structure format is used as a parameter for the routine.
• Transfer / Update Routines: They are defined at the InfoObject level. It is like the Start Routine. It is independent of the DataSource. 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 InfoPackage 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 maximum no. of key figures?
233
What is the maximum no. of characteristics?
248
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:
1. CHAR
2. NUMC
3. DATS
4. TIMS
How you’ll write date in BW?
YYYYMMDD
Same
Q1. SOME DATA IS UPLOADED TWICE INTO INFOCUBE. HOW TO CORRECT IT?
Ans: But how is it possible?.If you load it manually twice, then you can delete it by request.
Q2. CAN U ADD A NEW FIELD AT THE ODS LEVEL?
Sure you can.ODS is nothing but a table.
Q3. CAN NUMBER OF DATASOURCE HAS ONE INFOSOURCE?
Yes ofcourse.For example, for loading text and hierarchies we use different data sources but the same infosource.
Q4. BRIEF THE DATAFLOW IN BW.
Data flows from transactional system to analytical system(BW).DS on the transactional system needs to be replicated on BW side and attached to infosource and update rules respectively.
Q5. CURRENCY CONVERSIONS CAN BE WRITTEN IN UPDATE RULES. WHY NOT IN TRANSFER RULES?
Q6. WHAT IS PROCEDURE TO UPDATE DATA INTO DATA TARGETS?
Full and delta.
Q7. AS WE USE Sbwnn,SBiw1,sbiw2 for delta update in LIS THEN WHAT IS THE PROCEDURE IN LO-COCKPIT?
No lis in lo cockpit.We will have data sources and can be maintained(append fields).Refer white paper on LO-Cokpit extractions.
Q8. SIGNIFICANCE OF ODS.
It holds granular data.
Q9. WHERE THE PSA DATA IS STORED?
In PSA table.
Q10.WHAT IS DATA SIZE?
The volume of data one data target holds(in no.of records)
Q11. DIFFERENT TYPES OF INFOCUBES.
Basic,Virtual(remote,sap remote and multi)
Q12. INFOSET QUERY.
Can be made of ODSs and objects
Q13. IF THERE ARE 2 DATASOURCES HOW MANY TRANSFER STRUCTURES ARE THERE.
In R/3 or in BW??.2 in R/3 and 2 in BW
Q14. ROUTINES?
Exist In the info object,transfer routines,update routines and start routine
Q15. BRIEF SOME STRUCTURES USED IN BEX.
Rows and Columns,you can create structures.
Q16. WHAT ARE THE DIFFERENT VARIABLES USED IN BEX?
Variable with default entry
Replacement path
SAP exit
Customer exit
Authorization
Q17. HOW MANY LEVELS YOU CAN GO IN REPORTING?
You can drill down to any level you want using Nav attributes and jump targets
Q18. WHAT ARE INDEXES?
Indexes are data base indexes,which help in retrieving data fastly.
Q19. DIFFERENCE BETWEEN 2.1 AND 3.X VERSIONS.
Help!!!!!!!!!!!!!!!!!!!Refer documentation
Q20. IS IT NESSESARY TO INITIALIZE EACH TIME THE DELTA UPDATE IS USED.
Nope
Q21. WHAT IS THE SIGNIFICANCE OF KPI'S?
KPI’s indicate the performance of a company.These are key figures
Q22. AFTER THE DATA EXTRACTION WHAT IS THE IMAGE POSITION.
After image(correct me if I am wrong)
Q23. REPORTING AND RESTRICTIONS.
Help!!!!!!!!!!!!!!!!!!!Refer documentation
Q24. TOOLS USED FOR PERFORMANCE TUNING.
ST*,Number ranges,delete indexes before load ..etc
Q25. PROCESS CHAINS: IF U ARE USED USING IT THEN HOW WILL U SCHEDULING DATA DAILY.
There should be some tool to run the job daily(SM37 jobs)
Q26. AUTHORIZATIONS.
Profile generator
Q27. WEB REPORTING.
What are you expecting??
Q28. CAN CHARECTERSTIC CAN BE INFOPROVIDER ,INFOOBJECT CAN BE INFOPROVIDER.
Of course
Q29. PROCEDURES OF REPORTING ON MULTICUBES.
Refer help.What are you expecting??.Multicube works on Union condition
Q30. EXPLAIN TRANPORTATION OF OBJECTS?
Dev ---> Q and Dev ---> P
1. What is table partition?
A: SAP is using fact table partitioning to improve the performance. you can partition only on 0CALMONTH or 0FISCPER
2. What are the options available in transfer rule and when ABAP code is recquired during the transfer rule what important variables you can use?
A: Assign info object, Assign a Constant , ABAP routine or a Formula
3. How would you optimize the dimensions?
A: Use as many as possible for performance improvement; Ex: Assume that u have 100 products and 200 customers; if you make one dimension for both ,the size of the dimension will be 20000; if you make individual dimensions then the total number of rows will be 300. Even if you put more than one characterstic per dimension, do the math considering worst case senerio and decide which characterstics may be combined in a dimension.
4. What are the conversion routines for units and currencies in the update rule?
A: Time dimensions are automatically converted; Ex: if the cube contains calender month and your transfer structure contains date, the date to calender month is converted automatically.
5. Can you make an infoobject as info provider and why?
A. Yes, When you want to report on characterstics or master data, you can make them as infoprovider. Ex: you can make 0CUSTMER as infoprovider and do Bex reporting on 0 CUSTOMER;right click on the infoarea and select 'Insert characterstic as data target'.
6. What are the steps to unload non cumulative cubes?
A: 1. Initialize openig balance in R/3(S278)
2. Activate extract structure MC03BF0 for data source 2LIS_03_BF
3. setup historical material docus in R/3.
4. load opening balance using data source 2LIS_40_s278
5. load historical movements and compress without marker update.
6. setup V3 Update
7. load deltas using 2LIS_03_BF
7. Give step to step approach to archiving cubex.
A: 1. double click on the cube (or right click and select change)
2. Extras -> Select archival
3. Choose fields for selection(like 0CALDAY, 0CUSTOMER..etc)
4. Define the file structure(max file size and max no of data objects)
5. Select the folder(logical file name)
6. Select the delete options (not scheduled, start automatically or after event)
7. activate the cube.
8. cube is ready for archival.
8. What are the load process and post processing?
A: Info packake, Read PSA and update data target, Save Hierarchy, Update ODS data object, Data export(open hub), delete overlapping requests.
9. What are the data target administration task
A: delete index, generate index, construct database statistics, initial fill of new aggregates, roll up of filled aggregates, compression of the infocube,activate ODS, complete deletion of data target.
10. What are the parallel process that could have locking problems
A: 1. heirachy attribute change run
2. loading master data from same infoobject; for ex: avoid master data from different source systems at the same time.
3. rolling up for the same info cube.
4. selecting deletion of info cube/ ODS and parallel loading.
5. activation or delection of ODS object when loading parallel.
11. How would you convert a info package group into a process chain?
A: Double Click on the info package grp, click on the 'Process Chain Maint' button and type in the name and descrition ; the individual info packages are inserted automatically.
12. How do you transoform Open Hub Data?
A: Using BADI
13. What are the data loading tuning one can do?
A: 1. watch the ABAP code in transfer and update rules;
2. load balance on different servers
3. indexes on source tables
4. use fixed length files if u load data from flat files and put the file on the application server.
5. use content extractor
6. use PSA and data target inparallel option in the info package
7. start several info packagers parallel with different selection options
8. buffer the SID number ranges if u load lot of data at once
9. load master data before loading transaction data.
14. What is ODS?
A: Operations data Source . u can overwrite the existing data in ODS.
15. What is the use of BW Statistics?
A: The sets of cubes delivered by SAP is used to measure performance for query, loading data etc., It also shoes the usage of aggregates and the cost associated with then.
16. What are the options when definging aggregates?
A: * - groups accotding to characterstics
H - Hierarchy
F - fixed value
Blank --- none
17. How will you debug errors with SAP GUI (like Active X error etc)
A: Run Bex analyzer -> Business Explorer menu item -> Installation check; this shows an excel sheet with a start button; click on it; this verifies the GUI installation ;if u find any errors either reinstall or fix it.
18. When you write user exit for variables what does I_Step do?
A: I_Step is used in ABAP code as a conditional check.
19. How do you replace a query result from a master query to a child query?
A: If you select characterstic value with replacement path then it used the results from previuos query; for ex: let us assume that u have query Q1 which displaysthe top 10 customers, we have query Q2 which gets the top 10 customers for info object 0customer with as a vairable with replacement path and display detailed report on the customers list passed from Q1.
20. How do you define exception reporting in the background?
A: Use the reporting agent for this from the AWB. Click on the exception icon on the left;give a name and description. Select the exception from query for reporting(drag and drop).
21. What kind of tools are available to monitor the overall Query Performance?
22. What can I do if the database proportion is high for all queries?
23. How to call a BW Query from an ABAP program?
24. What are the extractor types?
25. What are the steps to extract data from R/3?
26. What are the steps to configure third party (BAPI) tools?
27. What are the delta options available when you load from flat file?
28. What are the table filled when you select ABAP?
29. What are the steps to create classes in SAP-BW
30. How do you convert from LIS to LO extraction?
31. How do you keep your self-updated on major SAP Develppments, Give an analytical
1. When should a DSO be used?
a) When Data needs to be overwritten.
b) When highly granular data is required in reports
c) All of the above. Ans : c
2. Can data be edited in PSA when the request is available in the Data Target?
a) Yes
b) No Ans : b
3. Can a request be reconstructed when there is no PSA?
a) No
b) Yes Ans : a
4. When can we have a Line Item Dimension?
a) When we have multiple Line Items
b) When we have a Single Characteristic in a Dimension
c) When we have less number of Characteristics in a Dimension. Ans : b
5. How do we decide on the Characteristics to be included in a Dimension?
a) When the fields (InfoObjects) have m: n relationship.
b) When the fields (InfoObjects) have 1: m relationship.
c) When the fields (InfoObjects) have m: 1 relationship. Ans : a
6. Criteria for selecting PSA and IDOC methods for Data Transfer
a) Load performance.
b) Query performance.
c) Volume of Data. Ans : c
7. All InfoProviders physically hold data
a) True
b) False Ans : b
8. When can we use InfoSets?
a) When Union is required.
b) When Joins are required.
c) All of the above Ans : b
9. Can InfoCubes be included in InfoSets in BI7?
a) No
b) Yes Ans : b
10. What needs to be done to make Attributes Navigable in Queries?
a) Exclude them from the Cube
b) Include them in the Cube
c) Nothing needs to be done. Ans : b
11. Can Queries be used after changes are made to the InfoProvider?
a) Yes
b) No
c) Maybe Ans : a
12. What needs to be done to make the queries work after changes are made to an InfoProvider?
a) Delete and re-create the queries.
b) Re-Generate the queries.
c) Nothing can be done. Ans : b
13. Can a single InfoSource be used to load Data to different InfoProviders?
a) Yes
b) No Ans : a
14. What are Aggregates?
a) Subset of an InfoCube.
b) Outset of a Cube.
c) None of the above. Ans : a
15. Definition of the Cube Dimensions with Master Data Tables can be checked from TCodes
a) LISTCUBE.
b) RSRV.
c) LISTSCHEMA.
d) All of the above. Ans : c
16. Pre-Configuring of ID’s like SID’s, DIM ID’s etc is called
a) Caching.
b) Blobbing.
c) Number Range Buffering.
d) None of the above. Ans : c
17. Application Component Hierarchies can be made available in BW by
a) Importing them in BW.
b) Transferring from SAP R/3.
c) Replicating in BW. Ans : b
18. Post Processing of DataSources is done in
a) RSA3
b) RSA4
c) RSA5
d) RSA6
e) None of the above. Ans : d
19. Testing the Extraction is done by
a) Running a Data Load.
b) Do an Extraction Check in SAP R/3.
c) Running a Query.
d) None of the above. Ans : b
20. How to check the Indices in a Cube?
a) InfoCubeMangePerformance
b) RSRT.
c) All of the above. Ans : c
FAQ in SAP Business Information Warehouse (a part SAP Netweaver)
1. What is table partition?
By using partitioning you can split up the whole dataset for an InfoCube into several, smaller, physically independent and redundancy-free units. Thanks to this separation, performance is increased when reporting, or also when deleting data from the InfoCube.
You can only partition a dataset using one of the two partitioning criteria ‘calendar month’ (0CALMONTH) or ‘fiscal year/period (0FISCPER). At least one of the two InfoObjects must be contained in the InfoCube.
2. What are the options available in transfer rule and when ABAP code is recquired during the transfer rule what important variables you can use?
Assign info object, Assign a Constant , ABAP routine or a Formula
3. How would you optimize the dimensions?
Use as many as possible for performance improvement; Ex: Assume that u have 100 products and 200 customers; if you make one dimension for both ,the size of the dimension will be 20000; if you make individual dimensions then the total number of rows will be 300. Even if you put more than one characterstic per dimension, do the math considering worst case senerio and decide which characterstics may be combined in a dimension.
4. What are the conversion routines for units and currencies in the update rule?
Use
Currency translation during the transformation enables you to convert data records from the source currency into a currency of the target of the transformation.
Currency translation in the transformation is generally performed using previously defined translation types. For more information, see Currency Translation Types.
Where required, you can perform currency translation with user-defined subprograms (formulas and routines). It is not currently possible to execute currency translation for DataStore objects using predefined translation types. You have to use routines instead.
Depending on the type of currency, there are two different types of key figures:
...
1. Key figures with a fixed currency (for example, DEM, USD)
With a fixed currency, the currency is fixed for the amount. The key figure refers specifically to the currency (for example DM, US$), so the currency does not have to be entered again in the data record.
2. Key figures with a variable currency (for example, foreign currency).
With a variable currency, the currency is determined by an InfoObject, (ODOC_CURRCY) for example.
For more information, see Creating InfoObjects: Key Figures.
Features
Transformations can be performed for key figures in two ways:
...
1. Every key figure in an InfoCube (target key figure) has a corresponding key figure in the source (source key figure). No currency translation takes place.
2. There is no corresponding source key figure in the InfoSource for the target key figure in the InfoCube.
a. You can assign a source key figure of the same type to the target key figure (sales revenue instead of sales quantity revenue, for example).
§ If the currencies of both of the key figures are the same, no currency translation can take place.
§ If the currencies are different, a translation can take place either using a currency translation type or by simply assigning a currency.
The following table provides an overview of possible combinations where the currency is not the same in the source and target key figures:
Source key figure currency Target key figure currency Currency translation (CT)
fixed variable No CT
fixed fixed CT
variable fixed CT
variable variable CT or assignment possible
b. If there is no corresponding source key figure of the same type, you have to fill the key figure of the target using a routine.
§ If the currency of the target key figure is fixed, currency translation is not performed. This means that if translation is required, you have to execute it in a routine.
§ If the currency of the target key figure is variable, you also have to assign a variable source currency to the routine. You can use input help to select a currency from the variable currencies that exist for the target. You have two options:
• You can select a variable currency and assign it.
• You can select a currency translation type and a currency into which you wish to translate (‘to’ currency).
By default, the ‘to’ currency is the target currency if it is included in the target.
Creating a routine for currency translation:
If you want to translate currencies during the transformation but currency translation is not available for one of the reasons stated above, you can create a routine. In transformation rule definition, choose Routine with Unit. You get an additional return parameter UNIT in the routine editor and the target currency is determined using the value of this parameter.
5. Can you make an infoobject as info provider and why?
Yes, we can make info object as a info provider. If "CNO"
is one of your info object for characterstics, select that
and right click on that and select the option as " Insert
the characterstic as Data Target". Now your info object
will become your info provider.
Use: We can do Master Data Reporting? with this procedure.
6. What are the steps to unload non cumulative cubes?
1. Initialize openig balance in R/3(S278)
2. Activate extract structure MC03BF0 for data source 2LIS_03_BF
3. setup historical material docus in R/3.
4. load opening balance using data source 2LIS_40_s278
5. load historical movements and compress without marker update.
6. setup V3 Update
7. load deltas using 2LIS_03_BF
7. Give step to step approach to archiving cubex.
1. double click on the cube (or right click and select change)
2. Extras -> Select archival
3. Choose fields for selection(like 0CALDAY, 0CUSTOMER..etc)
4. Define the file structure(max file size and max no of data objects)
5. Select the folder(logical file name)
6. Select the delete options (not scheduled, start automatically or after event)
7. activate the cube.
8. cube is ready for archival.
8. What are the load process and post processing.
Info packake, Read PSA and update data target, Save Hierarchy, Update ODS data object, Data export(open hub), deleteoverlapping requests.
9. What are the data target administration task
delete index, generate index, construct database statistics, initial fill of new aggregates, roll up of filled aggregates, compression of the infocube,activate ODS, complete deletion of data target.
10. What are the parallel process that could have locking problems
heirachy attribute change run
2. loading master data from same infoobject; for ex: avoid master data from different source systems at the same time.
3. rolling up for the same info cube.
4. selecting deletion of info cube/ ODS and parallel loading.
5. activation or delection of ODS object when loading parallel.
11. 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 descrition ; the individual info packages are inserted automatically.
12. How do you transoform Open Hub Data?
In BI7 environment , we can create Open Hub followed by Transformation. At the moment you pick up the Data Source for full update or delta update ,we can able to transform the open Hub data into a flat file(at workstation or Application Server) or into a Open Hub Table. DTP is used to accomplish the data Transfer.
13. What are the data loading tuning one can do?
16. What are the reporting performances one can do?
A : Aggregates, Change the read mode, Pre-calculate data etc
17. What are the data loading tuning one can do
A : Proptionately partition the request with data.
18. What is ODS
A : Most important Data staging structure available in BW
19. What is the use of BW Statistics
A : Provides the statistics information(Performance, response time, load time etc) of all the available objects in BW.
20. What are the options when defining aggregates
A : Please see help documentation there are lot of options
14. What is ODS?
To indicate it's location in the DWH lifecycle, let me tell you the data flow right from being picked up from your source systems till you have your corporate data in form of reports, dashboards & Scorecards.
Source Systems feed data to a intermediate db (called as Staging/Staging area). The data which is here is ready to be fed to a new DB (Operational Data Store). THe purpose of doing this is to allow for reporting on your OLTP meaning just reporting on your Source systems. This can be for adhoc reporting for a shorter periods of time (typically for 2-3 months or 1 quarter).
ODS now has the data from all of your Source Systems. This db acts as a source to your Data warehouse. ETL activities are performed on the ODS and the transformed data in loaded into your enterprise DWH.
It is often reffered to as an interim area for the warehouse.
It stores the current up-to-date cleansed information about the transactions(OLAP) and is available for simple quering.
It can staore upto a maximum of 90 days data.
15. What is the use of BW Statistics?
16. What are the options when definging aggregates?
While creating aggregates
- Contect menu of Data target (Infocube)
- Choose option maintain aggregates
- The system proposes the aggregates
- You can also create them manually
- System proposes the aggregates based on the statistics or on the queries executed with the specific period being mentioned.
- Aggregates have to be saved, activated and filled.
First of all identify which dimensions are really used in queries. based on that the necessary proposed aggregates need to be activated. Not all the proposed ones !!
17. How will you debug errors with SAP GUI (like Active X error etc)
Run Bex analyzer -> Business Explorer menu item -> Installation check; this shows an excel sheetwith a start button; click on it; this verifies the GUI installation ;if u find any errors either reinstallor fix it.
18. When you write user exit for variables what does I_Step do?
I_Step is used in ABAP code as a conditional check.
19. How do you replace a query result from a master query to a child query?
Using Result set Query.It is a nested query where result of first query used as entry values of second query.
20. How do you define exception reporting in the background?
21. What kind of tools are available to monitor the overall Query Performance?
22. What can I do if the database proportion is high for all queries?
23. How to call a BW Query from an ABAP program?
24. What are the extractor types?
If you want to load data from r/3 to bw system, you have to perform data extractions.The extractions are of two types.
Application
Cross Application
In this if you want to load standard data, then you go for LO
if it is customized, you go for Generic extractions, or COPA if it is related to finance.
You transfer data from r/3 and replicate those into BW.
25. What are the steps to extract data from R/3?
26. What are the steps to configure third party (BAPI) tools?
To extract the data from 3rd party system.
27. What are the delta options available when you load from flat file?
full update
delta update
28. What are the table filled when you select ABAP?
29. What are the steps to create classes in SAP-BW
30. How do you convert from LIS to LO extraction?
Maintain extract structure
2) maintain datasource
3)replicate datasource in BW
4)assign infource
5)maintain comm struct
6)maintain IC, UR
7)extract structure active and LIS update off
8)upload the open delta queue (from LIS)
9)empty setup tables
10)setup v3 update
11)initialize
12)IP
31. How do you keep your self-updated on major SAP Develppments, Give an analytical example.
6. WHAT ARE THE DIFFERENT VARIABLES USED IN BEX?
Variable with default entry
Replacement path
SAP exit
Customer exit
Authorization
What is table partition?
A: 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?
A: Double Click on the info package grp, click on the ‘Process Chain Maint’ button and type in the name and descrition ; the individual info packages are inserted automatically.
How do you replace a query result from a master query to a child query?
A: If you select characterstic value with replacement path then it used the results from previuos query; for ex: let us assume that u have query Q1 which displaysthe top 10 customers, we have query Q2 which gets the top 10 customers for info object 0customer with as a vairable 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 InfoObject be an InfoProvider, how and why?
• Yes, when we want to report on Characteristics or Master Data. We have to right click on the InfoArea and select “Insert characteristic as data target”. For example, we can make 0CUSTOMER as an InfoProvider 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 InfoSpoke. 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 DataSource 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 InfoCubes 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?
• Replicate DataSources
• Assign InfoSources
• Maintain Communication Structure and Transfer rules
• Create and InfoPackage
• Load Data
What are the delta options available when you load from flat file?
• The 3 options for Delta Management with Flat Files:
o Full Upload
o New Status for Changed records (ODS Object only)
o Additive Delta (ODS Object & InfoCube)
What are the extractor types?
• Application Specific
o BW Content FI, HR, CO, SAP CRM, LO Cockpit
o Customer-Generated Extractors
LIS, FI-SL, CO-PA
• Cross Application (Generic Extractors)
o DB View, InfoSet, Function Module
What are the steps involved in LO Extraction?
• The steps are:
o RSA5 Select the DataSources
o LBWE Maintain DataSources and Activate Extract Structures
o LBWG Delete Setup Tables
o 0LI*BW Setup tables
o RSA3 Check extraction and the data in Setup tables
o LBWQ Check the extraction queue
o LBWF Log for LO Extract Structures
o RSA7 BW Delta Queue Monitor
How to create a connection with LIS InfoStructures?
• LBW0 Connecting LIS InfoStructures to BW
What is the difference between ODS and InfoCube and MultiProvider?
• ODS: Provides granular data, allows overwrite and data is in transparent tables, ideal for drilldown and RRI.
• CUBE: Follows the star schema, we can only append data, ideal for primary reporting.
• MultiProvider: Does not have physical data. It allows to access data from different InfoProviders (Cube, ODS, InfoObject). It is also preferred for reporting.
What are Start routines, Transfer routines and Update routines?
• Start Routines: The start routine is run for each DataPackage 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 DataStructures. This structure or table can be accessed in the other routines. The entire DataPackage in the transfer structure format is used as a parameter for the routine.
• Transfer / Update Routines: They are defined at the InfoObject level. It is like the Start Routine. It is independent of the DataSource. 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 InfoPackage 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 maximum no. of key figures?
233
What is the maximum no. of characteristics?
248
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:
1. CHAR
2. NUMC
3. DATS
4. TIMS
How you’ll write date in BW?
YYYYMMDD
Same
Q1. SOME DATA IS UPLOADED TWICE INTO INFOCUBE. HOW TO CORRECT IT?
Ans: But how is it possible?.If you load it manually twice, then you can delete it by request.
Q2. CAN U ADD A NEW FIELD AT THE ODS LEVEL?
Sure you can.ODS is nothing but a table.
Q3. CAN NUMBER OF DATASOURCE HAS ONE INFOSOURCE?
Yes ofcourse.For example, for loading text and hierarchies we use different data sources but the same infosource.
Q4. BRIEF THE DATAFLOW IN BW.
Data flows from transactional system to analytical system(BW).DS on the transactional system needs to be replicated on BW side and attached to infosource and update rules respectively.
Q5. CURRENCY CONVERSIONS CAN BE WRITTEN IN UPDATE RULES. WHY NOT IN TRANSFER RULES?
Q6. WHAT IS PROCEDURE TO UPDATE DATA INTO DATA TARGETS?
Full and delta.
Q7. AS WE USE Sbwnn,SBiw1,sbiw2 for delta update in LIS THEN WHAT IS THE PROCEDURE IN LO-COCKPIT?
No lis in lo cockpit.We will have data sources and can be maintained(append fields).Refer white paper on LO-Cokpit extractions.
Q8. SIGNIFICANCE OF ODS.
It holds granular data.
Q9. WHERE THE PSA DATA IS STORED?
In PSA table.
Q10.WHAT IS DATA SIZE?
The volume of data one data target holds(in no.of records)
Q11. DIFFERENT TYPES OF INFOCUBES.
Basic,Virtual(remote,sap remote and multi)
Q12. INFOSET QUERY.
Can be made of ODSs and objects
Q13. IF THERE ARE 2 DATASOURCES HOW MANY TRANSFER STRUCTURES ARE THERE.
In R/3 or in BW??.2 in R/3 and 2 in BW
Q14. ROUTINES?
Exist In the info object,transfer routines,update routines and start routine
Q15. BRIEF SOME STRUCTURES USED IN BEX.
Rows and Columns,you can create structures.
Q16. WHAT ARE THE DIFFERENT VARIABLES USED IN BEX?
Variable with default entry
Replacement path
SAP exit
Customer exit
Authorization
Q17. HOW MANY LEVELS YOU CAN GO IN REPORTING?
You can drill down to any level you want using Nav attributes and jump targets
Q18. WHAT ARE INDEXES?
Indexes are data base indexes,which help in retrieving data fastly.
Q19. DIFFERENCE BETWEEN 2.1 AND 3.X VERSIONS.
Help!!!!!!!!!!!!!!!!!!!Refer documentation
Q20. IS IT NESSESARY TO INITIALIZE EACH TIME THE DELTA UPDATE IS USED.
Nope
Q21. WHAT IS THE SIGNIFICANCE OF KPI'S?
KPI’s indicate the performance of a company.These are key figures
Q22. AFTER THE DATA EXTRACTION WHAT IS THE IMAGE POSITION.
After image(correct me if I am wrong)
Q23. REPORTING AND RESTRICTIONS.
Help!!!!!!!!!!!!!!!!!!!Refer documentation
Q24. TOOLS USED FOR PERFORMANCE TUNING.
ST*,Number ranges,delete indexes before load ..etc
Q25. PROCESS CHAINS: IF U ARE USED USING IT THEN HOW WILL U SCHEDULING DATA DAILY.
There should be some tool to run the job daily(SM37 jobs)
Q26. AUTHORIZATIONS.
Profile generator
Q27. WEB REPORTING.
What are you expecting??
Q28. CAN CHARECTERSTIC CAN BE INFOPROVIDER ,INFOOBJECT CAN BE INFOPROVIDER.
Of course
Q29. PROCEDURES OF REPORTING ON MULTICUBES.
Refer help.What are you expecting??.Multicube works on Union condition
Q30. EXPLAIN TRANPORTATION OF OBJECTS?
Dev ---> Q and Dev ---> P
1. What is table partition?
A: SAP is using fact table partitioning to improve the performance. you can partition only on 0CALMONTH or 0FISCPER
2. What are the options available in transfer rule and when ABAP code is recquired during the transfer rule what important variables you can use?
A: Assign info object, Assign a Constant , ABAP routine or a Formula
3. How would you optimize the dimensions?
A: Use as many as possible for performance improvement; Ex: Assume that u have 100 products and 200 customers; if you make one dimension for both ,the size of the dimension will be 20000; if you make individual dimensions then the total number of rows will be 300. Even if you put more than one characterstic per dimension, do the math considering worst case senerio and decide which characterstics may be combined in a dimension.
4. What are the conversion routines for units and currencies in the update rule?
A: Time dimensions are automatically converted; Ex: if the cube contains calender month and your transfer structure contains date, the date to calender month is converted automatically.
5. Can you make an infoobject as info provider and why?
A. Yes, When you want to report on characterstics or master data, you can make them as infoprovider. Ex: you can make 0CUSTMER as infoprovider and do Bex reporting on 0 CUSTOMER;right click on the infoarea and select 'Insert characterstic as data target'.
6. What are the steps to unload non cumulative cubes?
A: 1. Initialize openig balance in R/3(S278)
2. Activate extract structure MC03BF0 for data source 2LIS_03_BF
3. setup historical material docus in R/3.
4. load opening balance using data source 2LIS_40_s278
5. load historical movements and compress without marker update.
6. setup V3 Update
7. load deltas using 2LIS_03_BF
7. Give step to step approach to archiving cubex.
A: 1. double click on the cube (or right click and select change)
2. Extras -> Select archival
3. Choose fields for selection(like 0CALDAY, 0CUSTOMER..etc)
4. Define the file structure(max file size and max no of data objects)
5. Select the folder(logical file name)
6. Select the delete options (not scheduled, start automatically or after event)
7. activate the cube.
8. cube is ready for archival.
8. What are the load process and post processing?
A: Info packake, Read PSA and update data target, Save Hierarchy, Update ODS data object, Data export(open hub), delete overlapping requests.
9. What are the data target administration task
A: delete index, generate index, construct database statistics, initial fill of new aggregates, roll up of filled aggregates, compression of the infocube,activate ODS, complete deletion of data target.
10. What are the parallel process that could have locking problems
A: 1. heirachy attribute change run
2. loading master data from same infoobject; for ex: avoid master data from different source systems at the same time.
3. rolling up for the same info cube.
4. selecting deletion of info cube/ ODS and parallel loading.
5. activation or delection of ODS object when loading parallel.
11. How would you convert a info package group into a process chain?
A: Double Click on the info package grp, click on the 'Process Chain Maint' button and type in the name and descrition ; the individual info packages are inserted automatically.
12. How do you transoform Open Hub Data?
A: Using BADI
13. What are the data loading tuning one can do?
A: 1. watch the ABAP code in transfer and update rules;
2. load balance on different servers
3. indexes on source tables
4. use fixed length files if u load data from flat files and put the file on the application server.
5. use content extractor
6. use PSA and data target inparallel option in the info package
7. start several info packagers parallel with different selection options
8. buffer the SID number ranges if u load lot of data at once
9. load master data before loading transaction data.
14. What is ODS?
A: Operations data Source . u can overwrite the existing data in ODS.
15. What is the use of BW Statistics?
A: The sets of cubes delivered by SAP is used to measure performance for query, loading data etc., It also shoes the usage of aggregates and the cost associated with then.
16. What are the options when definging aggregates?
A: * - groups accotding to characterstics
H - Hierarchy
F - fixed value
Blank --- none
17. How will you debug errors with SAP GUI (like Active X error etc)
A: Run Bex analyzer -> Business Explorer menu item -> Installation check; this shows an excel sheet with a start button; click on it; this verifies the GUI installation ;if u find any errors either reinstall or fix it.
18. When you write user exit for variables what does I_Step do?
A: I_Step is used in ABAP code as a conditional check.
19. How do you replace a query result from a master query to a child query?
A: If you select characterstic value with replacement path then it used the results from previuos query; for ex: let us assume that u have query Q1 which displaysthe top 10 customers, we have query Q2 which gets the top 10 customers for info object 0customer with as a vairable with replacement path and display detailed report on the customers list passed from Q1.
20. How do you define exception reporting in the background?
A: Use the reporting agent for this from the AWB. Click on the exception icon on the left;give a name and description. Select the exception from query for reporting(drag and drop).
21. What kind of tools are available to monitor the overall Query Performance?
22. What can I do if the database proportion is high for all queries?
23. How to call a BW Query from an ABAP program?
24. What are the extractor types?
25. What are the steps to extract data from R/3?
26. What are the steps to configure third party (BAPI) tools?
27. What are the delta options available when you load from flat file?
28. What are the table filled when you select ABAP?
29. What are the steps to create classes in SAP-BW
30. How do you convert from LIS to LO extraction?
31. How do you keep your self-updated on major SAP Develppments, Give an analytical
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