6.interview questions
TRANSCRIPT
[Type the company name]
Application Life-cycle: SDLC(SOFTWARE DEVELOPMENT LIFE CYCLE)
This is the End-to End process of an application in the organisation (From
requirements gathering to production support).
There are 4 phases in the life-cycle
1. Requirements Gathering
2. Development
3. Testing
4. Production or Support
1. Requirements Gathering
Business analyst(BA): He is the person or a mediator between the client and the
organisation.
First Business Analyst is going to interact with the client to know about the client
business and pain-areas, from that business analysis BA will prepare the
document called as Business requirement document or BRD or FSD(Functional
Specification document) or SPEC.
From the BRD,the development team will prepare the HLD and LLD.
HLD(High-level-document): Divide the BRD into different modules for requirement
analysis, prepared by developers.
LLD(Low-level-document): Gives the detailed information about each entity in the BRD
or HLD, prepared by developers.
GAP Analysis:This is the comparision between client requirement and reporting
tool features like is the tool fulfill all the requirements of the client or not.
POC(Proof of Concept):This is the dummy or a duplicate model where the
development team will cook the data manually and prepares a sample model
which is going to send for the client’s approval.
Note:The end product should be same with the POC.
2. Development
There are 2 parts in development
ETL development: ETL developers will prepare a data-model with all dimensions
and facts.Also build an integrated dataware-house from the heterogeneous data
sources.
Reporting development:Once the DWH is built,the reporters will configure the
repository and generate the reports asa per the client’s requirement.
3. Testing
Tesing is the major part in any application or product development.There are 3 types of
testing in the OBIEE application development.
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Unit Testing:The developer will test the own stuff.
Peer-Reviews:Test the application within the organisation as the application
developed.
UAT(User Acceptance Test):This is a client test testing,the application will be
tested by some other company.
4. Production or Support
The company need to give the application support for one month by default.After that
based on the client’s decision, the development company or some other company will
give the production support.
Obiee interview questions and answers
1.Date format issue while export to excel format
A)Answers–>column propeties–>custom CSS style options(bottom of the window)–
>check the custom css style –>Give the following date format
—-mso-number-format:”mm\/dd\/yyyy\ hh\:mm\:ss AM\/PM” or ” mso-number-format:\
@”
Change the format based on you requirement.
2. When i logged into the analytics not able to see all the options available for
administrator?
A)First logged in as a administrator into Em, manage the privileges which is required for
the user
3.I want to display the 4 narrative views in a single compound layout,but first narrative
view width is 1000 and the other 3 views width should be 500.Is it possible?
A)No,With a single compound view we can’t achieve.
4.How can i sort values of column in subject area not in report ?
A)We can sort the column in 3 ways
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1.Ascending order
2.Descending order
3.Based on another column
In Rpd we can sort the column based on the another column
BMM layer—>properties of the column_sort–>General—>Sort order column —->select
the column_base(column_sort will be sorted based on the column_base).
4.Can we call multiple action from a single actionlink?
A)Yes,We can call the multiple action links from a single action link based on the
conditions.
5.What is the difference between joins in physical layer and BMM layer?
A)Both are same,but can give the complex conditions in BMM layer.The Query always
fire from physical layer only.
6.I have 2 tables in DataBase table1 and table2
a)Imported together with keys and foreign keys?
bJoins will be automatically established in the physical layer.
b)Imported together only with keys?
Ans:-Keys will remain but joins not
c)Dragged the 2 tables from physical layer to BMM layer(along with Joins),which act like
fact table and which act like dimension table?
Ans:-Primary key—–Dimension
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Foreign key——-Fact
d)Same as (c) but without Joins?
Ans:-Both act like fact tables in BMM layer
7.You recently changed the columns of your presentation catalog as your manager
wants to enforce naming standards for all customer facing applications. What happens
to all the dashboard requests written prior to this change?Do they function properly or
do they appear broken?”If yes, they will function”, How does they work?”If not,reports
appear broken”, what can you do to fix this?Give examples?
Ans:-If alias table is available for presentation table then all the reports work fine.
8. I have configured the repository(3 layers) and saved.I have generated some reports
and saved.If I change the presentation catalog name then it is showing that you don’t
have permissions to access this subject area in answers.How can you fix this?
Ans:-Goto Advanced tab(In answers) Change the subject area name and set XML it will
automatically display the subject area.
PERFORMANCE TUNNING FOR REPORTS AND DASHBOARDS
9.You come Morning to the office And all the users are complaining about the OBIEE
reporting system is very slow (dashboards). What is your approach to resolve the issue?
Ans:
1. First check NQServer.log
2. Admin Tool -> click Session Manager. Check if there is any bottleneck and
accordingly resolve.
Refresh the sessions………
3. Analytics or Answers -> Administration-> Manage Sessions
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Check the physical query and execute from the back-end(BE).
10.Performance Tuning at real time
A)Performance Tuning is the huge topic to answer;
let’s take step by step approach as follows…
Check whether the same query is running or anyone update the query.If the same query
is running then follow the steps given below,
When you open the dashboard page, first figure out whether Prompt or Report is taking
more time.
If it is prompt, check for any multi select prompts which are taking time to load all
values.. (best practice is set default values).
If Report is taking longer time, set some default filters and query for just couple of
records and check the report performance.
Take physical SQL from the session log (if SQL is not generated check for log level
whether it is less than 2).
Run this Physical SQL in the TOAD or any SQL Editor.
Check Explain plan for the cost of the query.
Hash Joins/Cartesian Joins are always kills performance.
Some-times, Force Inner-join also helps to force the tables to have inner-join between
two tables.
Check are there any “Full Table Scans” happening instead of Index Scan.
Consult your DBA for the Stats.
OBIEE PRESENTATION LAYER BEST PRACTISES
Presentation catalog should map to one Business model & mapping layer(BMM) layer
objects only.
Use parent folders and sub-folders to group facts and similar dimensions together.
Avoid the use of aliases when a new presentation column is created.
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The presentation columns in a table should be sorted alphabetically if no specific order
is asked by the customer.
Make proper use of the permissions in this layer like authentication and authorization.
Don’t use special symbols (“) in column name, though its permitted.
Presentation columns should not have the same name as presentation table.
Eliminate unneeded objects to reduce user confusion.
Limit number of objects in folder to 7-12 (for performance tuning only).
Use object description field to convey information to users when they hover the mouse
in answers on a presentation column.
Keep names short to have space on reports and give the meaningful table names and
columns names to identify easily on subject areas. Remove primary key columns and
other unnecessary columns that does not going to use in the creation of the reports.
Try to create separate folder for each data mart (HR, operation, SCM, sales) if it is
coming from same logical layer.
Get costumer sign off of the presentation layer structure before building reports. This
will avoid later replacements of columns which affects the report.
BMM LAYER BEST PRACTISES
1. Always run Global Consistency Check before releasing a repository:
Whenever we make changes to a repository, always be sure to run Global Consistency
Check. It is bad practice to release a repository that still contains consistency check
errors. In some cases, consistency errors prevent Oracle BI server from loading the
repository. Use the Consistency chec k manager to identify and debug check messages.
Note: Whenever you do Consistency check , Right Click the Changed Business Model
Object and go for Check consistency rather than using the Global Consistency Check.
This will minimize the time needed for Consistency Check.
2. Minimize the use of Snow-flakes. Always go for Star Schema’s:
Every logical fact table must join to atleast one logical dimension table.
Note that when the source is a fully de-normalized table or flat file, you must map its
physical fact columns to one or more logical fact tables, and its physical dimension
columns to logical dimension tables.
3. Create dimension hierarchies for every Dimension in the Business Model:
Even if a meaningful hierarchy definition cannot be thought of, just create one with the
Grand Total Level and Detail Level. For Dimension Hierarchies the ‘Number of Elements
at this level’ should increase from 1 at grand Total to the corresponding distinct values
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at each level. This can be approximate values; need not be the exact ones. Define keys
at each level of the Hierarchy.
4. Don’t keep unwanted physical columns in the Logical Layer:
5. Give Meaning ful Names to the Logical columns. Avoid assigning a logical column the
same name as a logical table or Business Model Object:
6. Logical Fact & Dimension table columns:
Always assign a primary key for logical dimension tables. All logical dimension columns
should be renamed in a way that is meaningful to users.
Bring only required columns into BMM layer for reporting.
Do not assign logical primary key for logical fact columns.
Create “dummy” measures to group facts.
7. Use Multi User Development Environment:
Use the Multi-User Development facility if there are multiple developers. Multiple
developers to connect “online” to the same repository file and Making changes is not
recommended.
Multi User Development allows user to define a series of projects with in the repository
file, where each project is a subset of the entire repository. If developers want to make
changes, they can check out a project to a local machine make and test the changes,
and then check the modifications back into the master repository file.
8. Level-based Metrics:
When creating level-based measures, make sure that all appropriate fact sources map
to the appropriate level in the hierarchy using aggregation content. You set up
aggregation content in the levels tab of the Logical Column dialog for the measure.
Note that this is different from the content tab of the Logical dialog for the measure.
Note that this is different from the content tab of the logical table source dialog, which
is used to specify the grain of the source tables to which it maps. You only need to set
up aggregation content in the levels tab of the logical column dialog for level-based
measures. For measures that are not level based, leave the logical level field bank.
9. Separate business model:
Even if you have only a single data source or schema in the physical layer, or you have
only one physical data source for the repository, it is still good practice to break out the
physical objects into multiple business models in the BMM layer to represent the
independent areas of functionality.
10. Arrange the logical columns alphabetically if customer does not require any. This
will save time when you revisit:
11. Fix the warnings if any, don’t ignore it:
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12. Performance Tuning:
Minimize the use of conditional checks and ‘CASE WHEN’ usage in the formula of
Logical columns. This will affect performance. Instead make proper use of the where
clause content filter of the LTS if the condition applies to all the columns/ measures in
the logical table.
Make proper distinction between count and count distinct. If you are counting on a
unique value column don’t use count distinct. This will affect performance.
Avoid dimensions in Fact tables and avoid measures in dimension tables.
OBIEE INTERVIEW QUESTIONS
1.What you did in physical layer,BMM layer and Presentation layer?
Ans: Physical layer:Physical layer is a connection between database and repository
by using connection pool.We can import the data from the different data sources, no.of
connection pools, aliases like tables and columns, duplicate tables, opaque views and
physical joins etc.
BMM layer:Also called as Logical layer, Actually we implemented the logic here.We
can do the calculations, create the logical tables and columns, establish the joins like
physical and logical or complex joins, dimensions, level-based-metrics etc.
Presentation layer:We can show only the content which we want to show the end-
user, We can implement authorization and authentication, Implicit fact column and sort
order column etc.
2.What are Level-Based-Metrics(LBM)?How you use in your project?
Ans: Level-based-metrics show the measures at different levels based on the
dimension hierarchy. Generally LBMs will use to display the data at month, week and
day level. To show this we will create the alias measure columns. Explain more details
from your project.
3.What is Dimension Hierarchies?Explain the procedure to create the
Hierarchy?
Ans: Below link give the complete procedure for creating the dimension hierarchy..
http://oracletechnotalk.blogspot.in/2012/04/creation-of-hierarchy-in-
obiee.html
4.What is Sort order columns?
Ans: We can sort the columns at 2 levels
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1. Repository:At the presentation layer,sort the one column values based on another
column
2. Answers:At the criteria tab->columns->sort the column values either ascending or
descending order based on the requirement.
5.Rate yourself in SQL?
Ans: Here you need answer very carefully because based on your rating they are ready
to fire the questions on SQL. You have the minimum knowledge in SQL like select
statement, joins, performance concepts etc.
6.What is Implicit fact table and Implicit fact column?
Ans: A common fact table for dimension tables is called as Implicit fact table. An
Implicit fact column is a column in a Implicit fact table, we can select the best path
between the dimensions. Implicit fact column is decided in presentation layer.
7.Can we handle the nulls?
Ans: Yes,we can handle either in repository and answers.
ifnull(column_name,0)->at expression of the measure column
8.What is the use of connection pool?
Ans: We can create different no.of connection pools in the project. It has the database
connection details, no.of minimum users can access the application.
9.What is security in OBIEE?
Ans: Security in OBIEE can be implemented in 2 ways.
1. Authentication:Verify and validate the users against the system.
2. Authorization:Validate the users against the Data.
10.What is Authentication?How can we implement?
Ans: Verify and validate the users against the system.We can implement the
Authentication in 4 ways
1. External table
2. Operating system
3. Data base
4. LDAP
11.What is Authorization?How can we implement?
Ans: Validate the users against the Data. Data can be limited the users by
1. Object level
2. Data level
3. Reports/Dashboard level
Did u get the data from any other data sources? If yes how?
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Yes,ofcourse client will provide the data in different formats like excel sheets, files,
cubes etc. We can import the data by creating the drivers for data sources.
Can i import the data directly from other sources to repository?
yes, we can directly import the data to repository
How to set the logging level in repository?
manage->identity->goto the user->set the logging level
The logging level for developer:min 2
The logging level for Administrator:upto 7
In production phase the logging level should be disabled. We can set the logging level
for a specific request at answers
Have you ever worked with ETL-tools?
As a reporting developer, i know the flow of ETL process. I never worked on that.The ETL
people takecare of everything.
Which type of schema you are used in your project?
Actually most of the projects are designed like a star-schema.My project is also used
star-schema as a data model.
What is star and snow-flake schema?
For complete details about star and snow-flake schema
http://oracletechnotalk.wordpress.com/2012/04/10/basic-dataware-housing-
interview-questions/
What is fact and dimension table?
The detailed description of fact and dimension tables
http://oracletechnotalk.wordpress.com/2012/04/10/basic-dataware-housing-
interview-questions/
What is the flow of your porject?
Every project must follow the software development life cycle.
Generally,the porject flow may like requirements gathering, Development(ETL and
Report), testing and Production.The flow of project may differ from project to project
based on domain like retail, telecom, healthcare, construction etc.
The complete knowledge on SDLC
http://oracletechnotalk.wordpress.com/2012/04/22/obiee-application-development-
life-cycle/
What is Dataware housing?
http://oracletechnotalk.wordpress.com/2012/04/10/basic-dataware-housing-
interview-questions/
Rate yourself in SQL?
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OBIEE developer must have the knowledge on sql because he need to test his own
stuff.Minimum knowledge of SQL is required for dataware housing developers.The rating
should be dependent on the person knowledge.
Tell me About yourself?
This is the major interview question for freshers and experienced. Everyone should
prepare before going to the interview.
Experienced:Tell ur name with experience what you have with current and previous
organization and then explain the porject what you done. If they expecting more then
give your educational details but no need to mention the family back ground.
What are your roles and responsibilities in your current project?
As a OBIEE developer,the reponsibilities like repository configuration and reports
generation based on the client requirements. At the end we need to implement the
security.
From where you start your work in daily routine?
Daily i got a mail from my reporting manager with a attached document. It includes all
the requirements and details of the work.
What is the architecture of OBIEE?
http://oracletechnotalk.wordpress.com/2012/04/15/obiee-architecture/
Explain the 3 layers of the repository?
http://oracletechnotalk.wordpress.com/2012/04/15/obiee-architecture/
What is connection pool and how many connection pools you have in your project?What
is the purpose?
Actually connection pool is a link between repository and database. For more details use
the link
http://oracletechnotalk.blogspot.in/search?q=connection+pool
We can use multiple connection pools for to increase the performance. The no.of
connection pools may dependent on the project. We created different connection pools
for
security implementation,users and variables creation etc.
What is the difference between Obiee 10g & 11g?
OBIEE 10g:
We have 2 joins, foreign key join and complex join.
We have only level-based hierarchy in the logical layer.
All the configuration settings will be done at NQSconfig file.
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OBIEE 11g:
we have only 1 join, new join.
We have different hierarchies; level-based hierarchies,parent-child hierarchies,ragged
hierarchies,skipped hierarchies.
All the configuration settings will be done at the enterprise manager.
we have option like look-up table.
In answers,the chart view renamed as graph.
which version of OBIEE you are using?
Go to help in the repository of your project. There we can get the exact version of
OBIEE.
What is the difference between OCI and ODBC?
OCI will be specific to the oracle database but the ODBC connection, we can use with
any data source.
Have you ever worked on Joins?If yes how?
Yes, In physical layer i worked on joins based on the data-modelling document.
DATAWAREHOUSE FUNDAMENTALS
Dataware house is a
Non-volatile: Permanent data(stores historical data or past data)
Subject-oriented: Data will be stored according to the subjects(like data-marts)
Integrated:Make a single source from heterogeneous sources
Time-variant: Data changed over a period of time
Dataware Housing: It is process of storing and retrieving data from warehouse.
Steps Involved from database to datawarehouse:
1. Extract the data from the heterogeneous sources and load into staging area(Source
Dependent Loading)
2. Apply transformations on staging area and load into datawarehouse (Source
Independent Loading)
3. Generate the reports from the datawarehouse by using a reporting tools like OBIEE,
Cognos etc.
We can generate the reports from the OLTP or databases but the performance may
decrease because the no.of joins are more.
why we do reporting?
Reporting is an essential event for analysis of the data of the specific organisation.
Anyone can analyse like management, users, partners etc.We can forecast the values
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by using the reports or reporting tool. Reporting will be exist in all domains like Retail,
Tele-communication, Insurance, Banking, Education, Public sector industries or factories
and private sector industries.Analysis of data is everywhere like small-scale, medium-
scale and large-scale industries.
PHYSICAL LAYER IN OBIEE
Physical Layer:The name itself is saying,it is having the direct relation between the
repository and database.This is the one o f the most important layer in the
repository.The query will be executed from the physical layer only.Joins in the other
layers should be same with the physical layer.We can’t rename the object names in the
physical layer.In this layer we can import the data,creating connection pools,alias
tables,duplicate tables,opaque views, keys and joins.
Data sources:We can Import the data from different Data sources like oracle, my-sql,
excel sheets, XML data and cubes(OLAP and ESS base) by using different drivers. Data
will be imported with key or without keys.
Connection pool:We can create a multiple connection pools for single repository to
increase the performance.These are used for accessing users,variables and
implementing the security etc.
Tables:Alias and duplicate tables will be created in the physical layer.
Alias table:It is copy of parent table and always functionally depending on the parent
table.Alias table will be created for re-use the same table for different purpose.
Duplicate table:It is a copy of parent table but don’t have the relation,once created.
Keys:If u import the tables without keys,here we can create the keys based on the
data-modelling.The joins will be established in the physical layer only based on the
primary and foreign key relation.
Opaque views:Opaque view is physical select statement,which does not occupy any
space in the repository.We can deploy or un-deploy from repository to database.
PHYSICAL LAYER BEST PRACTISES
PHYSICAL LAYER
Don’t import foreign keys from the database.
Avoid circular joins by using alias tables.
Use a different connection pool for different data sources.
Use a different connection pool for variables,data sources and security configuration.
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Establish the joins in the physical layer based on the data-modelling or client
requirement.
Use the max no.of users for each connection pool.
Delete the unused physical objects from the layer by using Remove unused physical
object utility.
Update the row-count by using Update physical layer to check the database connection.
Avoid hints in the physical table level
Don’t establish join between fact and fact table
Avoid to create a view or physical select statement in the physical layer
Remove the unused connection pools,it might lead to BI server crash as it continuously
ping to the connection.
Better to disable the database features in the DB-features configuration file.
Always use a data-ware house or OLAP(online analytical processing) system as a
database for geenrating reports.
Use proper naming convention for physical table and alias table also.
Always define your catalog under projects.
Ensure to check “execute queries asynchronously” option in the connection pool details.
CONFIGARATION AND LOG FILES IN OBIEE
Configuration files:These are the default files for every tool, it will store the default
settings of the tool. We can change the settings based on the requirement.
Configuration files of OBIEE are
Configuration files of RPD:
NQSconfig.ini: We can configure the RPD into BI server, setting-up the cache
parameters, security by-passing, usage-tracking, setting up the time-zone, date, time-
format,language and buffer stack size properties.
DBfeatures.ini: We can enable/disable the database features.
NQSCluster.ini: Maintains the servers in the machine(When multiple servers existed
on the same machine).By default in disable mode.
Log files of RPD: Log files are Informative files of anything.
NQServer.log: It will give the information about the BI server like when server starts
and stops and why server is not started.
NQSQuery.log:Information about the query manger like how much time it will take to
execute the query and performance of the query.
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NQSAdministration.log:Information about the administration tool like problems with
administration tool and all.
NQS Scheduler.log:Information about the schedulers like administration tool and
analytics.
Configuation files of Analytics :
Instanceconfig.xml: It will store all the settings of presentation service or Analytics
like reports, dashboards and all the elements .
Web-catalog: Web catalog is a folder,it will store the all the settings of a
application.Maintains an individual catalog for application is the best-practice for
deploying the application.
In OBIEE 11g,all the configuration settings will be done at enterprise manager.
Enterprise manager is a third-party server, here all the settings are manages like
configuration of RPD, cache management, users and groups, web catalog settings.
OBIEE ARCHITECTURE
(Oracle Business Intelligence Enterprise Edition) latest version is 11.1.1.5 or 6.It is a
reporting tool for generate the reports to analyse the data.OBIEE has 2 default servers
BI server and Presentation server.It has 6 components in the architecture
1.Presentation services(Answers or Analysis)
2.Presentation server
3. Repository
4. BI server
5. Database connection(ODBC (Open database connectivity) or OCI (Oracle call
Interface))
6. Enterprise Data ware House
Presentation Services:This is a front-end page for users or clients.User can see the
reports from the Answers or Analysis page.It contains answers, dashboards, account
details privileges of the specific users.We can the reports and dashboards based on the
client requirement.By starting the presentation server,we can operate the presentation
services.
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Repository:It is also called as RPD or RCU.Metadata settings are configured in the rpd
level.It has 3 layers
Physical layer:It has the direct connection with the database.We can apply the joins
between fact tables and dimension tables based on the data-modelling.
Business model and mapping layer:The logical changes will be done here like creating
logical joins(complex joins),new columns or tables,hierarchies etc.
Presentation layer:The objects will be visible to the users what placed in
the presentation layer.We can apply the security setting in the presentation layer.
We can operate the Repository settings by starting the BI server.we can open the RPD
in either online or offline mode
Database connection:This is the database connection between database and
OBIEE.The database connection is either ODBC or OCI.
Data-ware House: Data-ware House is a huge data storage space for retrieving data.
OBIEE architecture interview questions and answers
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What are the major components in the OBIEE architecture?
a. Client
b. Presentation services(along with cache)
c. Repository
d. Database connection
e. Enterprise datawarehouse
f. Scheduler(along with cache)
What are the different layers of OBIEE Repository?
a. Physical Layer
b. Business Model and Mapping Layer
c. Presentation Layer
What are the folders available in OBIEE?
Oracle BI(Administration)
Oracle BIdata(analytics)
What are the Key Configuration Files in OBIEE
NQSConfig.ini,
DBfeatures.ini,
NQSCluster.ini,
odbc.ini,
instanceconfig.xml
What are the different Log files in OBIEE?
NQServer.log
NQSQuery.log
NQSAdministration.log
NQS Scheduler.log
What are the minimum services needed to load a repository file onto memory and view
a dashboard which has reports that have been refreshed on a scheduled basis?
BI server (Administration Tool)
Presentation Server (Analytics or Answers)
Scheduler server (Scheduling the jobs)
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What is the location of the administration configuration files?
drive:\OBIEE 11g\instances\instance1\config\oracleBIservercomponent\
coreapplication_obis1\file name
What is the location of the repository?
drive:\OBIEE 11g\instances\instance1\bifoundation\oracleBIservercomponent\
coreapplication_obis1\repository
What is the location of the presentation services configuration files?
drive:\OBIEE 11g\instances\instance1\config\oracleBIpresentationservices
component\coreapplication_obis1\instanceconfig.xml
What is the location of the administration log files?
C:\OBIEE11g\instances\instance1\diagnostics\logs
OBIEE Interview Questions & Answers
1. Explain the Architecture of OBIEE and what each components do?
Answer :- OBIEE Consists of Presentation Services(Web),Oracle BI (Analytics Engine)
Server
The client (Answers) constructs sql and passes it to the Analytic Engine and then the
Oracle BI (Analytic Engine) parses the physical sql to the Datasources and retrieve the
data back to the Engine and presents to the presentation Services .
2. How to get sql from obiee for reports?
Answer :- There are many ways to get the sql
a. Modify the request and click Advanced in that you get xml code and also the actual
sql.
b. In the catalog Manager click Tools –>Create Report .In the Create Report Window –>
Click Request SQL and save the sql to the physical path in your PC.
c. Enable Loglevel to 2 in the OBIEE Admin Tool from Mange-> Security and enable the
log level to 2 by clicking properties for the user, then go to the NQQuery.log in
BI_HOME/OracleBI/Server/Logs.You will find the SQL for that User.
d. By clcking Administration->Manage sessions-> view sql.
3. How will you do sort in Reports in OBIEE Answers.
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Answer :- Click modify and then click sort (order by icon) on the relevant column in the
criteria pane.
4. How will you do different types of narrative Reports in OBIEE?
Answer:- By clicking modify request and Narrative View and by giving @1 for the first
column result and @2 for the 2nd column and son on and we can also give a heading for
No Results by clicking the Narrative view.
5. How will you create Interactive Dashboards ?
Answer:- By clicking Administration and Manage dashboards and by adding column
selector also by using view selector etc.and also by using prompts.
6. What is write-back in obiee ?
Answer:- In Reports of Answer you can give a column as updatebale and then view the
reports,this option is called write back.
7. How will you execute Direct SQL in OBIEE?
Answer:- By clicking Direct Database Request below the subject area in Answers.
8. How will you create report from two subject areas
Answer:- From the Criteria Pane of the Report Created from First Subject Area
come to the bottom of the page and click combine request. but the options are limited
for combining like union etc..
9. How will you Port changes for dashboards,reports,rpd from development to
production?
Answer:- For the RPD use the Merge option in Admin Tool and for dashboards and
reports use Content Accelerator Framework.
10. What are the different types of variables in OBIEE? explain
Answer:- There are two types of variables in obiee.
a.Repository variable.
This variable is for the whole repository.
b.session variable . session variable can be system variable and non system variable.
system variable uses NQ_SESSION. —- (system reserved variable). examples of non
system variables are user defined filters etc.
11. How will you enable or disable caching in the system level and table level?
Answer:- In the NQSConfig.ini file use ENABLE under CACHE Section for System Level
for tables .If you want to enable the cache at table level , open the repository in offline
mode(not the current working repository). this should be different from the current
repository and click enable or disable the cache . right click the table and properties and
click the cache or deselect the cache. then merge the repository with the current
working one.
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12. How will you go about adding additional column to the repository in the presentation
layer?
Answer :- Check whether the table is already existing if so add in physical layer ,then
BMM and then Presentation layer, then reload server metadata ,then it will be visible to
all users.
13. How will effect the changes for a report , if for certain users only the column
heading in the report should be changed?
Answer:- Using session variables for that user.
14. What is a table alias in obiee? and where and how will you create it.
Answer:- Table alias can be created by right clicking the table in the physical layer then
click alias,
Table alias is mostly used for creating self joins.
15. Have you created Hierarchy in OBIEE. if so where and how?
Answer:- Yes we can create hierarchy in BMM Layer of OBIEE in dimensions for the
dimension tables. this can be done by right clicking the dimension table and click create
dimension and then we should manually define the hierarchy and its levels.
16. What is Level Based Metrics.How will you create it?
Answer:- Leval-base matrics means, having a measure pinned at a certain level of the
dimension. Monthly Total Sales or Quarterly Sales are the examples.
To create a level based measure, create a new logical column based on the original
measure (like Sales in the example above). Drag and drop the new logical column to the
appropriate level in the Dimension hierarchy (in the above example you will drag and
drop it to Month in Time Dimension.
17. What are the different layers of OBIEE Repository?
Answer:- Physical Layer, Business Model and Mapping Layer, and Presentation Layer.
18. What is Authentication? How many types of authentication.
Answer:- Authentication is the process by which a system verifies, through the use of a
user
a. Operaing system autentication
b. External table authentication
c. Database authentication
d. LDAP authentication
19. What are the different types of security you have worked in OBIEE?
Answer :- Object Level and data level.
20. What is a bridge table ?
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Answer:- If you want to connect two tables where there is no relation ship you can use a
thrid bridge table for connecting them which will have common columns in both tables,
this is used in BMM Layer.
21. You come Morning to the office. and all the users are complaining about the obiee
reporting system is very slow(dasboards). what is your approach to resolve the issue?
Answer:- Mainly check NQServer.log and in Admin Tool -> click Session Manager. check
if there is any bottleneck and accordingly resolve.
22. What are the different log files in OBIEE?
Answer:- Following are the different log files inOBIEE
NQServer.log , NQQuery.log, NQSAdminTool.log etc.
There are mainly 25 Configuration files available in obiee.
23. What are the Key Configuration Files in OBIEE?
Answer:- NQSConfig.ini, NQSCluster.ini, odbc.ini, instanceconfig.xml
24. How will change port of obiee answers?
Answer:- By changing its port in instanceconfig.xml
25. What is ClusterServices in OBIEE ? Why its used?
Answer:- To Scale up the Performance by clustering and distributing the services across
multiple Servers ClusterServices are used.
26. Can you change the location of the OBIEE Repository?
Answer:- No, Not in Standalone OBIEE Install. you can give shared location in
NQSCluster.ini if the OBIEE is clustered.
27. How many BI Services Node can be clustered together?
Answer :- 16
28. Can you run multiple rpd’s in a Single OBIEE Instance?
Answer :- No . you should create another instance in the same server , then its possible.
29. How will you implement security in obiee,so that subjects areas accessed by one
group are not accessed by another group.
Answer:- Using Security Manger in OBIEE Admin Tool, by creating two user groups and
allowing only part of the subject area for one group and other part to the other user
group.
30. What is SCD type 1 and 2.
Answer:- SCD is slow changing dimensions. in type 1 we replace the changed dimension
with old dimension. in type 2 we use surrogate keys and keep both the records(rows).
Advantage of SCD2 is we keep history of the old dimensiont.
31. What is Star Schema and SnowFlake Schema?
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Answer:- Star is one fact and many dimensions where as Snowflake design is one fact
and many dim’s and dim’s can have additonal dim relations.
32. How to startup OBIEE in Linux?
Answer:-
./run-sa.sh start #starts obi server
./run-saw.sh start #start saw server
./run-sch.sh start #start scheduler
33. How you generally Approach to ur Analytics Project?
Answer:- Any project should start from defining the scope of the project and the
approach
should be not to deviate from the scope.
Then the project should be functionally divided into smaller modules generally done by
project managers along with technical and functional leads.
The functional leads then decide on majorly three things:
According to the defined scope of the project they start gathering requirements while
interacting with the clients.
They had a discussion with the technical leads and try to reach a solution.
Technical leads decides what schemas to create and what requirements are going to
fulfill by that schema.
Technical leads discuss all this with the developers and try to close requirements.
Simultaneously testing and deployment is planned in a phased manner.
34. How we are going to decide which schema we are going to implement in the data
warehouse?
Answer:- One way is what is mentioned in Question above.
If one ask you to blindly create schemas for the warehouse without knowing any
requirements,
You can simply first divide the schemas on the basis of functional areas of an
Organization which are similar to the modules in an ERP like sales, finance, purchase,
inventory, production, HR etc.
You have to broadly describe the expected analysis an organization would like to do in
every module. This way you would be able to complete at least 40-50 % of the
requirements. To move ahead, study the data and business and you can create few
more schemas.
35. What are the Challenges You Faced while making of Reports?
Answer:- Making of an report has never been a difficult task. But problem comes when
users are reluctant to adopt a new system. Many developers have experienced that if
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they are not able to create the report in exactly the way they used to see, they will keep
asking for the changes. Developers approach should be to first show them what they
want to see and then add more information in the report.
36. What you will do when your Report is not Fetching Right Data?
Answer:- This is the biggest problem in report creation and verification. There could be
two reasons for report not fetching the right data.
1. Mostly clients do not have correct data in their database and on top of that to correct
the results they make some changes at the report level to bring the desired result which
you may not e aware of while creating the reports. Clients try to match the data with
their existing reports and you never get the correct results. you try to discover the
things and at later stage come to know of all these problems and you are held
responsible for this delay. Hence always consult the SPOC(Single Point of Contact) and
try to understand the logic they have used to generate their reports.
2. If the database values are correct, there there could be a problem with the joins and
relations in the schema. You need to discover that analyzing and digging deep into the
matter.
37. How analytics Process Your Request When you Create your Requests?
Answer:- Oracle BI server converts the logical SQL submitted by the client into
optimised physical SQL which is then sent to the backend database. Also in between it
performs various tasks like converting the user operations like user selections to form a
logical SQL, checking and verifying credentials, breaking the request into threads(as
Oracle BI is a multi threaded server), processes the requests, manages the cached
results, again converting the results received from the database into user presentable
form etc.
38. From where u Get the Logical Query of your Request?
Answer:- The logical SQL generated by the server can be viewed in BI Answers.
39. What are the Major Challenges You Faced While Creating the RPD??????
Answer:- Every now and then there are problems with the database connections but the
problem while creating the repository RPD files comes with complex schemas made on
OLTP systems consisting of lot of joins and checking the results. Th type of join made
need to be checked. By default it is inner join but sometimes the requirement demands
other types of joins. There are lot of problems with the date formats also.
40. What are Global Filter and how thery differ From Column Filter?
Answer:-
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Column filter- Simply a filter applied on a column which we can use to restrict our
column values while pulling the data or in charts to see the related content.
Global filter- This filter will have impact on across the application.
41. How to hide Certain Columns From a User?
Answer:- We can hide a column in Application access level security
Do not add the column in the report
Do not add the column in the presentation layer.
42. How to Enable Drills in a Given Column Data?
Answer:- To enable Drill down for a column, it should be included in the hierarchy in
OBIEE.
Hyperion IR has a drill anywhere feature where dont have to define and can drill to any
available column.
43. How the users Created Differs From RPD/Answers/Dashboards Level?
Answer:- RPD users can do administrator tasks like adding new data source, create
hirarchies, change column names where as Answers users may create new charts, edit
those charts and Dashboard users may only view and analyse the dashboard or can edit
dashboard by adding/removing charts objects.
44. How Online/Offline mode impact Development and Delpoyment????
Answer:-
Online Mode- You can make changes in the RPD file and push in changes which will be
immediately visible to the users who are already connected. This feature we may use in
production environment.
Offline mode- can be useful in test or development environment.
45. What is Guided Navigation?
Answer:- Guided navigation is a feature of Oracle BI Interactive Dashboards that
enables the content and layout of Oracle BI Interactive Dashboard to change
dynamically based on changes in the information being analyzed.
Specifically, sections in a dashboard page can be set up and only appear when there is
“interesting” information in the data.
SCENARIOS
How change the column heading dynamically
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We can change the column heading dynamically by passing the presentation variable in
column heading, to achieve this follows following steps
1) Log into the Business Intelligence analytics with the link
http://Machine_name:port/analytics
The port will be 7001 if OBIEE install with simple install option with default port
configuration or it will 9704 if OBIEE is install with enterprise option default port
configuration
2) Click on New-> Dashboard Prompt
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3) Select the column prompt
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4) Select the Column Calendar Date from Sample Sale Lite subject area
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5) Set the presentation variable Date and save it
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6) Then go for report creation click New-> Analysis
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7) Pulled the column field to display on the reports
8) Click on right most button of field and select column property
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9) On column properties dialog box navigate over column format and select check box
Customize heading. Set the presentation variable @{Date} in column heading
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10) Save the report and pulled it on Dashboard page and select the date from prompt
11) The column heading will change according to value select in the prompt
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OBIEE Security Enforcement
OBIEE SECURITY ENFORCEMENT – LDAP AUTHENTICATION
AUTHENTICATION IN OBIEE
Some authentication methods used by Oracle BI server are
Database
LDAP
Oracle BI server (repository users) – I do not recommend this method for medium to
large implementations. It will be difficult to manage.
I will discuss on setting up LDAP in this article.
SETTING UP LDAP OR WINDOWS ADSI IN OBIEE
Microsoft ADSI (Active Directory Service Interface) is Microsoft version of LDAP server.
Most of the steps to setup of either Microsoft ADSI or LDAP server are similar. In either
case, you would need help from your network security group/admin to configure LDAP.
They should provide you with the following information regarding the LDAP server
LDAP server host name
LDAP Server port number
Base DN
Bind DN
Bind Password
LDAP version
Domain identifier, if any
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User name attribute type (in most cases this is default)
REGISTERING AN LDAP SERVER IN OBIEE
In Oracle BI repository, go to manage security.
Create a new LDAP server in OBIEE Security Manager
With the help from your network security group/administration, fill out the following
information
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Next in the Advanced tab, based on the kind of LDAP server you have and its
configuration, make the necessary changes.
For Microsoft ADSI (Active Directory Service Interface), choose ADSI and for all others
leave it unchecked.
Most of the times, Username attribute would be automatically generated. For Microsoft
ADSI It is sAMAccountName; for most of the LDAP servers it is uid or cn. Check with your
network security group/administrator on what is the username attribute for your LDAP
server. Make a note of the user name attribute you will need it later.
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Now we need to create an Authentication initialization block. In administration tool,
under Manage go to Variables.
Under Action, go to New -> Session -> Initialization Block
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Configure the session initialization block. Give it a name and click on Edit Data Source.
In the pop up window, choose LDAP from the drop down box and then click on Browse.
You can also configure a LDAP server here by clicking on “New”. In the browse pop up
window choose the LDAP server you would like to use.
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Next we need to create variables. User and Email are the common variables normally in
play.
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Upon clicking on OK, a warning pops up on the usage of User session variable (User
session variable has a special purpose. Are you sure you want to use this name). Click
yes.
Next enter the LDAP variable for username. sAMAccountName in the case of ADSI as
configured in the LDAP.
Next following similar steps create a variable for Email. In addition, depending on you
need, you can bring additional variables from the LDAP server.
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Connection Pools – Best Practices
CONNECTION POOLS – BEST PRACTICES
Most of the times not much thought is given to defining connection pools while
developing rpd. Improperly defined connection pool would affect the OBIEE performance
and user experience. Here are some of the things to consider while defining connection
pool.
Change the default maximum connections. The default is 10. Based on your system
usage change the value that is more realistic to your system usage
Create a separate connection pool for execution of session variables
Create a separate connection pool for the execution of aggregate persistence wizard.
Remember that you need to give the schema user owner credentials for this connection
pool as the wizard creates and drops tables
If need be create a separate connection pool for VVIPs. You can control who gets to use
the connection pool based on the connection pool permissions.
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FRIDAY, 28 DECEMBER 2012
Mapping Analyst for Excel in Informatica 8.6 OBIA
Mapping Analyst for Excel in Informatica 8.6 OBIA
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Hi friends , hope you all have come across the Mapping Analyst for
Excel in Informatica Power Centre 8.6 version.I would like to just give a brief
introduction about the same.In the coming days we will discuss more about the same.
As you all know before when we start a DWH project we need to gather business
requirements from the client.It takes some time for us to analyze the functionality of the
project and then make that as a document in technical perspective for ETL. This process
is too tedious as a lot of valuable development time is spent gathering business
requirements and then translating them into technical specifications, and then
converting these specifications to PowerCenter data integration mappings.So in order
to avoid this Informatica has come with a new feature called Mapping Analyst for Excel.
Mapping Analyst for Excel simplifies the complexity in mapping by directly converting
the data in the Excel into Informatica Mappings regardless of the format.This will mainly
help the Analyst.They can follow a specific template for defining the source and target
in the Excel and then send the same to the Developers who can directly convert this
template into Informatica Mappings and execute the workflows.
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How to convert the date field in OBIEE report to a desired date format
How to convert the date field in OBIEE report to a desired date format?
CAST (expr AS type) is a conversion function in OBIEE that changes the data type of a
value or a null value to another data type.This is one solution to change the
datatype,but when I tried with this the column heading in report changed to different
colour and my client didn't liked that solution.So I tried another solution.Follow the
below steps and screenshots.
1.Go to Column Properties tab
Select column properties tab
2.Select Data Format tab
3.Check “Override Default Data Format” box
4.Select “Date Format” field dropdown as custom/as required in your report. If you
select “Date Format” field dropdown as custom then specify “Custom Date Format” field
as required in report.
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How to convert the date field in OBIEE report to a desired date format
How to convert the date field in OBIEE report to a desired date format?
CAST (expr AS type) is a conversion function in OBIEE that changes the data type of a
value or a null value to another data type.This is one solution to change the
datatype,but when I tried with this the column heading in report changed to different
colour and my client didn't liked that solution.So I tried another solution.Follow the
below steps and screenshots.
1.Go to Column Properties tab
Select column properties tab
2.Select Data Format tab
3.Check “Override Default Data Format” box
4.Select “Date Format” field dropdown as custom/as required in your report. If you
select “Date Format” field dropdown as custom then specify “Custom Date Format” field
as required in report.
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OBIA Architecture and Functionality Overview
OBIA Architecture and Functionality Overview
The architecture for Oracle Business Intelligence Applications (OBIA) includes several
components. Understanding these components is prerequisite to a successful OBIA
implementation. A brief description of each component is included below the diagram.
OBIEE:
OBIA is a set of prebuilt reports for every business module like Financial, HR, Sales,
Order Management, etc.
In order to have pre-built reports we need to have prebuilt rpd (generic business logic).
The rpd is built on top of pre-defined tables (dimensions and facts). The tables reside in
a BI database(OLAP).
Informatica:
Prebuilt OBIA Informatica mappings are created to extract data from several data
sources (OLTP) and load to BI database (OLAP) tables. These data sources include
Oracle EBS, JD Edwards, Peoplesoft, and other ERP systems.
A set of SDE, SIL and PLP together loads data into one BI fact or dimension table
SDE Mapping or Source Dependant Loads: Are used to extract data from and Data
Source to staging
SIL Mapping or Source Independant Loads: Are used to load data from staging to the
target OBI tables (dimensions and facts)
PLP or Post Load Processes: Are sometimes used to transform data after it is in a fact
table, or add to data after it is in a fact table.
Informatica structure: An informatica workflow includes one or more sessions sessions.
Each session includes one mapping.
A workflow is started that runs one or more sessions. The logic of each session is
defined in a mapping.
DAC:
DAC acts like a trigger to run the workflows in Informatica.
DAC contains Execution Plans which can be scheduled or run any time. These Execution
Plans are designed to do an incremental or a full load.
Within each Execution Plan there are several subject areas, each subject area contains
all the tasks which are associated to workflows in Informatica that loads data to the
dimensions and facts to build the corresponding subject area.
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OBIA Architecture and Functionality Overview
OBIA - Naming Convention
Table
Table Types Used by the Oracle Business Analytics Warehouse
Table Suffix Description
Aggregate tables (_A) Contain summed (aggregated) data.
Dimension tables (_D) Star analysis dimensions.
Staging tables for
Dimension (_DS)
Tables used to hold dimension information that have not
been through the final ETL transformations.
Staging tables for Usage
Accelerator (WS_)
Tables containing the necessary columns for the ETL
transformations.
Dimension Hierarchy
tables (_DH)Tables that store the dimension's hierarchical structure
Dimension Helper tables
(_DHL)
Tables that store M:M relationships between two joining
dimension tables.
Staging tables for Staging tables for storing M:M relationships between two
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Dimension Helper
(_DHLS)joining dimension tables.
Fact tables (_F) Contain the metrics being analyzed by dimensions.
Fact Staging tables (_FS)
Staging tables used to hold the metrics being analyzed by
dimensions that have not been through the final ETL
transformations.
Column
Suffix Description In Table Types
_CD Code field_D, _DS, _FS, _G,
_GS
_DT Date field_D, _DS, _FS, _G,
_DHL, _DHLS
_I Language Independent Code. 1) _D, _MD
_ID_ID columns are used in _FS tables. They correspond to the
_WID columns of the corresponding _F table._FS
_FLG Indicator or Flag._D, _DHL, _DS, _FS,
_F, _G, _DHLS
_WIDIdentifier generated by Oracle Bl linking dimension and
fact tables, except for ROW_WlD._F, _A, _DHL
_NAMEName corresponding to the code column (columns ending
with _CODE)_D, _F, _A
_DESCLong Description corresponding to the code column
(columns ending with _CODE)_D, _F, _A
Posted by yogi at 23:14 No comments:
MERGE Two Repository in OBIEE 11G
Hi All,
Here are the simple steps to merge two repository in obiee 11g
You should have three rpd's for merging
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1) Your Current RPD. (BISAMPLE.rpd) >>Current RPD<<
2) The RPD to be merged (the one you newly worked on) - sandeep.rpd >>Modified
RPD<<
3) Dummy RPD. In My case dymmy.rpd
If you don't have a dummy. rpd , create a new rpd from the admintools (do not import
metadata).
ok now we are all set to start the merging.
Step 1: Open your Current RPD, ie BISAMPLE.rpd in my case and select the merge
option.
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Step 2: Provide the details of RPD as given below.
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Select dummy.rpd as your original rpd and Sandeep.rpd as the modified rpd
and click next >>
Step 3: Define Merge Strategy
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In this case select Decision = Current
Click next finish >>>
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The repository merge is now complete.
variables in OBIEE 11g.
There are basically 4 different types of variables in OBIEE 11g.
Session Variables
Repository Variables
Presentation Variables
Request Variables.
Session Variables:
As the name suggests, session variables are created during the creation of session i.e.,
as soon as a user logs into the BI server. So, Every login has its own session variable.
There are two types of session variables
System (which are defined by OBIEE and are reserved)
Non-System which are defined by developers.
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Session Variables can be created only through Oracle BI Administration Tool.
Referencing session variable:
For displaying session variables, we should use
@{biServer.variables['NQ_SESSION.VariableName']} .
For using session variables in expression, we should use
VALUEOF(NQ_SESSION.“VariableName”).
Repository Variables:
A repository variable is a variable that has a single value at any point in time.
There are two types of repository variables
Static (which changes only if admin or developer changes it value)
Dynamic ( value is refreshed using a query)
Repository variables can be created only through Oracle BI Administration Tool.
Referencing repository variable:
For displaying repository variables, we should use @{biServer.variables.VariableName}
or @{biServer.variables['VariableName']}.
For using repository variables in expression, we should use VALUEOF(“VariableName”)
for static variable and for dynamic variable VALUEOF(“Dynamic Initialization Block
Name”.“VariableName”).
Presentation Variable:
A presentation variable is a variable which can be created as a part of creation of
dashboard prompts. Dashboard prompts must be either Column Prompt or Variable
Prompt.
The value of presentation variable is set by the prompt for which it is created (upon user
selection).
Referencing presentation variable:
For displaying presentation variables, we should use either
@{variables.VariableName}[Format]{DefaultValue} or
Format and DefaultValue are optional
Format is useful to format the data for e.g., for Date, format can be MM/DD/YYYY. Note:
Default Value is not formatted.
@{scope.variables['VariableName']}.
Scope should be used if you create variables with same name.
Scope can be analyses, dashboard etc.
Order of precedence is analyses, dashboard pages, dashboards.
For using presentation variables in expression, we should use @{“VariableName”}
{DefaultValue}. Default value is optional.
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Request Variable:
Request Variable is used to overwrite the value of session variable and it happens only
during request initiation to the database from column prompt.
Can be created only during the creation of column prompt.
1.What is the difference between OBIEE 10g and OBIEE 11g?
A Database Repository must be created before installing OBIEE by using Repository
Creation
Utility(RCU) tool
OBIEE 11g uses a WEBLOGIC server as Applictaion server whereas OBIEE 10g uses OC4J
Many configuration settings (such as uploading a repository into BI server) can be done
using EM
OBIEE 11g displays table names and COLUMN NAMES while mapping whereas OBIEE
10g
displays only table names
In 10g Users and Groups(or Roles) are created in repository whereas in 11g Users and
Groups are
created in EM
Groups no longer exist and are replaced by Application roles. Data level security is
implemented by
using Application roles to which users belong to.
In Presentation Catalog, AuthenticatedUser role is used instead of Everyone group
We can model LOOK UP TABLE is repository
Creating hierarchy in Presentation layer
New time series functions PERIOD ROLLING and AGGREGATE AT is introduced
TIME SERIES functions can be created in the front end also
AGGREGATE PERSISTENCE WIZARD creates indexes automatically
SESSION VARIABLES are intialised only when they are used
In addition to the existing views, Map View is introduced in 11g
RAGGED and SKIPPED HIERARCHY are supported in 11g
KPI's and SCORECARD's are introduced in 11g
ACTION LINKS, MASTER-DETAIL reports, SELECTION STEPS are introduced
SELECT_PHY SICAL is supported
REQUESTS are renamed as ANLAY SIS
IBOTS are renamed as AGENTS
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CHARTS are renamed as GRAPHS
2. What is an Alias table and why is it used?
An alias table (Alias) is a physical table which references a different physical table as its
source
Advantages of using alias table:
It allows you to reuse any existing table more than once, without having to import it
several times
It can be used to avoid circular joins by setting multiple tables each with different keys,
names or joins For example: Order date and Shipping date may reference to same
column in the time dimension table. By using alias you can create two different
tables OrderDate and ShippingDate
It can be used for best practice naming conventions as you can rename the table and
leaving the original physical table as it is
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