Business Intelligence FAQs ,Interview Questions Answers

1/06/2011 No Comment
BI Question Answers,Business Intelligence FAQs ,Interview Question Answers asked in top companies in India ,USA like IBM,HP,Cisco,Wipro ,Infosys and TCS

Q.What is Business Intelligence?
A.Business intelligence (BI) is a broad category of applications and technologies for gathering, storing, analyzing, and providing access to data to help enterprise users make better business decisions.Business Intelligence is process of exploring data in order to take strategic decisions whether to drive profitability or to manage costs.

It is a broad category of application programs and technologies for gathering, storing, analyzing, and providing access to data to help enterprise users make better business decisions. BI applications include the activities of decision support, query and reporting, online analytical processing (OLAP), statistical analysis, forecasting, and data mining.This technology based on customer and profit oriented models that reduces operating costs and provide increased profitability by improving productivity, sales, service and helps to make decision making capabilities at no time.

Q.Name some of the standard Business Intelligence tools in the market?
A.Some of the standard Business Intelligence tools in the market According to there performance

6.Business objects
8.Microsoft integrated services

Q.What is OLAP?
A.OLAP stands for Online Analytical Processing. It is used for Anaytical reporting.This helps to do Business analysis of you data, but normal reporting tools are not supporting to Business analysis. This is the major difference between reporting tool and OLAP tool.It is a GateWay between the Business user and DWH.

A.Cubes in a data warehouse are stored in three different modes. A relational storage model is called Relational Online Analytical Processing mode or ROLAP, while a Multidimensional Online Analytical processing mode is called MOLAP. When dimensions are stored in a combination of the two modes then it is known as Hybrid Online Analytical Processing mode or HOLAP.

This is the traditional mode in OLAP analysis. In MOLAP data is stored in form of multidimensional cubes and not in relational databases. The advantages of this mode is that it provides excellent query performance and the cubes are built for fast data retrieval. All calculations are pre-generated when the cube is created and can be easily applied while querying data.

The disadvantages of this model are that it can handle only a limited amount of data. Since all calculations have been pre-built when the cube was created, the cube cannot be derived from a large volume of data. This deficiency can be bypassed by including only summary level calculations while constructing the cube. This model also requires huge additional investment as cube technology is proprietary and the knowledge base may not exist in the organization.

The underlying data in this model is stored in relational databases. Since the data is stored in relational databases this model gives the appearance of traditional OLAP’s slicing and dicing functionality. The advantages of this model is it can handle a large amount of data and can leverage all the functionalities of the relational database.

The disadvantages are that the performance is slow and each ROLAP report is an SQL query with all the limitations of the genre. It is also limited by SQL functionality. ROLAP vendors have tried to mitigate this problem by building into the tool out-of-the-box complex functions as well as providing the users with an ability to define their own functions.

HOLAP technology tries to combine the strengths of the above two models. For summary type information HOLAP leverages cube technology and for drilling down into details it uses the ROLAP model.

Q.Comparing the use of MOLAP, HOLAP and ROLAP
A.The type of storage medium impacts on cube processing time, cube storage and cube browsing speed. Some of the factors that affect MOLAP storage are:

1.Cube browsing is the fastest when using MOLAP. This is so even in cases where no aggregations have been done. The data is stored in a compressed multidimensional format and can be accessed quickly than in the relational database. Browsing is very slow in ROLAP about the same in HOLAP. Processing time is slower in ROLAP, especially at higher levels of aggregation.

2.MOLAP storage takes up more space than HOLAP as data is copied and at very low levels of aggregation it takes up more room than ROLAP. ROLAP takes almost no storage space as data is not duplicated. However ROALP aggregations take up more space than MOLAP or HOLAP aggregations.

3.All data is stored in the cube in MOLAP and data can be viewed even when the original data source is not available. In ROLAP data cannot be viewed unless connected to the data source.
4.MOLAP can handle very limited data only as all data is stored in the cube.

Q.How to Import universes and user from business object 6.5 to XI R2, it is showing as some ODBC error is there any setting to change?
A.You can import universes through import option in file menu.if ur odbc driver is not connecting then u can check ur database driver

Q.What are the various modules in Business Objects product Suite?
1.Supervisor :It is the control center for the administration and security of your entire BusinessObjects deployment.
2.Designer :It is the tool used to create, manage and distribute universe for BusinessObjects and WebIntelligence Users. A universe is a file that containe connection parameters for one or more database middleware and SQL structure called objects that map to actual SQL structure in the database as columns,tables and database.
BusinessObjects Full client Reporting tool :Helps to create businessobjects reports based on the universe and also from the other data sources.
BusinessObjects Thin client Reporting tool :Helps to querry and analysis on the universe and also share the report among other users. It doesn't require any software, just need a webbrowser and the system connected to the businessobjetcs server.

3.Auditor :Tool is used for monitor and analysis user and system activity.

4.Application Foundation : This module covers a set of products which is used for Enterprise Performance Management (EPM). The tools are
1.Dashboard manager
3.Performance Management Applications

Q.What is Hyperion? Is it an OLAP tool? what is the difference between OLAP and ETL tools? What is the future for OLAP and ETL market for the next five years?
a.Its an Business Intelligence tools. Like Brio which was an independent product bought over my Hyperion has converted this product name to Hyperion Intelligence.

Q.Is Hyperion an OLAP tool?
You can analyse data schemas using this tools.
1.OLAP: Its an online analytical processing tool. There are various products available for data analysis.
2.ETL: Extract , Transform and Load. This is a product to extract the data from multiple/single source transform the data and load it into a a table,flatfile or simply a target.
There is a quite a bit compitation in the market with regard to the ETL product as well as the OLAP products. These tools would definately be widely used for data load and data analysis purpose.

Q.Explain the Dashboard in the business intelligence.

1.Dashboard: A dashboard in business intellgence allows huge data and reports to be read in a single graphical interface. They help in making faster decisions by replying on measurable data seen at a glance. They can also be used to get into details of this data to analyze the root cause of any business performance. It represents the business data and business state at a high level. Dashboards can also be used for cost control. Example of need of a dashboard: Banks run thousands of ATM’s. They need to know how much cash is deposited, how much is left etc.

2.SAS Business Intelligence : SAS business intelligence has analytical capabilities like statistics, reporting, data mining, predictions, forecasting and optimization. They help in getting data in the format desired. It helps in improving quality of data.

Q.Explain the SQL Server 2005 Business Intelligence components.  
1.SQL Server Integration Services:- Used for data transformation and creation. Used in data acquisition form a source system.
2.SQL Server Analysis Services: Allows data discovery using data mining. Using business logic it supports data enhancement.
3.SQL Server Reporting Services:- Used for Data presentation and distribution access.

Q.How would you improve the performance of the reports.
A.Performance of the reports starts with analyzing the problem.The problem could be with database, Universe or the report itself
1.Analyzing the database
a.Run the SQL from the report on an oracle client like SQL Navigator or toad after passing in all the parameters.
b.Identify if the SQL takes considerable less time than the report. If yes then the problem is with the Universe or with the report if no then
c.Run an explain plan on the SQL
d.Look to see if all the statistics are computed, indexes are built and the indexes are used
e.Check to see if aggregate tables can be used ( Aggregate tables are useful if the data can be concised to 1/10th of fact data)
f.Check to see if data has increased and usage of materialized views could help.
1.Creating materialized views enable to pre -run the complex joins and store the data.
2.Most of the DW environment has a day old data hence they don’t have lot of overhead.
3.Running a report against a single materialized table is always faster then running against multiple tables with complex joins.
4.Indexes can be created on this materialized view to further increase the performance.
g.Check to see if the performance of the SQL can be increased by using hints ,if yes then add a hint to the report SQL and freeze the SQL, this might have an additional overhead of maintaining the report

2.Analyzing the Universe
a.Check is all the outer joins are properly created and remove unnecessary outer join
b.Business Objects as such do not use Multi Pass SQL , Multi pass SQL is a technique a software use to break down a complex SQL into multiple smaller SQLs. Hence a query using one fact table and three dimension tables can be broken down into two, one between the dimension tables and the second between the first result and the fact table. This can be achieved in BO by creating Derived Tables. The derived table would be based on three dimension tables and the reports hence can use one derived table and one fact table instead of four tables.
c.The Keys tab allows you to define index awareness for an object. Index awareness is the ability to take advantage of the indexes on key columns to speed data retrieval.
1.In a typical data warehousing environment surrogate keys are used as primary keys instead of natural keys , this primary key may not be meaningful to the end user but Designer can take advantage of the indexes on key columns to speed data retrieval.

2.The only disadvantage is it would not return duplicate data unless the duplicate data has separate keys
d.Check to see if the size of the universe has increased recently
e.Try to create a different universe for new requirements
f.Under extreme conditions the AUTOPARSE parameter in the param file can be turned off, this could be too risky if not handled properly.

3.Analyzing the Report
a.Check to see if there are any conditions which could be pushed into universe as Filters
b.Check to see if a formula has multiple usage ,turn this to a variable
c.Check if there are any variables which are not used, remove them.
d.Remove any additional filters or alerters on the report
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