Thursday, 10 April 2014

OBIEE Interview Question - I

Default Port- 9704 for Analytics and 7001 for both em and console.
OBIEE Architecture
OBIEE (Oracle Business Intelligence Enterprise Edition) latest version is 11.1.1.5 or 6.It is a reporting tool for generate the reports to analyses 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, and 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.

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-modeling.
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, is really every table is set to cacheable by default?
No, by default some of the physical tables are not set cacheable because those tables are maintained with large volume of data, so it may lead to performance issues.
We can Observe the cacheable option : table->properties

I have a report, built with columns like order_no, order_date, order_locetc..In the report i can able to see the data perfectly but when i download the report to excel the data column is showing the unexpected result. Is it a expected scenario? If yes, how can i resolve this?
Yes, this is an expected behavior, so we have to externally tell the BI serer to follow a specific format when download the report.
Steps:
Analysis->column properties-> Custom CSS style format->specify the date  format ->mso-number-format:”\@”

I have a dashboard prompt, which is a edit box. I want to use the edit box as case in-sensitive filter in my dashboard page. Is it possible?
Yes, It is possible you can achieve this required my changing the configuration setting in theNQSconfig.INI file.
CASE_SENSITIVE_CHARACTER_COMPARISON = OFF;//by default ‘ON’ enabled
Restart the services and observe the behavior of the Edit box.

Business Intelligence:
Business Intelligence is a methodology to represent the raw data into a meaningful format for the business purpose.It always deals with the data warehouse to handle or process the large volume of data.Meaning,the data analysis will make users to understand the business and able the take the decisions.

How does it helps in the real world scenarios?
Generally BI show the data in a tabular/pictorial format that will support the business users to analyse the data w.r.t trending and making the business decisions.

How can we master on Business Intelligence?
The only source to become a master in BI is Explore Business Domain Knowledge.Ingeneral, only the domain Experts can build the best solution for business because they have an awareness of the business functionality and KPIs.
Business Intelligence also deals with Data Integration, Transformation, Management and Quality by using Different Tools like MSBI(Microsoft Business Intelligence) , OBIEE(Oracle Business Intelligence Enterprise Edition) etc.

Future of Business Intelligence:
Business Intelligence will exist in the world till the business exists because the word itself is saying it is “BUSINESS INTELLIGENCE”.

What is the difference between Obiee 10g & 11g?
OBIEE - 11g 
1.    64-Bit
2.    Server Name – Weblogic  Server or you can call Oracle Enterprise Manager Fusion Middleware
3.    Repository and Configuration in EM - Oracle Enterprise Manager Fusion Middleware
4.    User, Group Created in Fusion middleware console and Role Created in EM
5.    You can integrate with any application for example Salesforce, SAP or all CRM tool. Because 11g have separate console where you can do deployment, Integration.
6.    Time series function - Ago, Today and period rolling. Added new TSF i.e. PERIODROLLING
7.    Dimension Hierarchies - Level-Based Hierarchy and Parent-Child Hierarchy, introduces new  DH i.e. Parent-Child Hierarchy
8.    Repository password protection. Need RPD password. 
9.    The RPD now has a password. This security is partially to protect the RPD access, 
10.  KPI and Scorecard was introduces in OBIEE 11g
11.  REQUESTS have been renamed to ANALYSIS
12.  IBOTS have been renamed to AGENT
13.  CHARTS have been renamed to GRAPHS
14.  Presentation columns have been renamed to attribute columns
15.  11g supports Ragged & Skip Level Hierarchy
16.  Column selector in 11g can be defined on multiple columns
17.  The ability to create custom print layouts for dashboard page
18.  You can now change the repository password from the command line using the obieerpdpwdchg utility
19.  Breadcrumbs -It allows users to keep track of their locations within programs or documents
20.  New Graphs  Waterfall graph, Stacked graph and 100% Stacked graph in n 11.1.1.7
21.  Map view is a new view type that presents data in spatial form
22.  11g allows us to work with multiple subject areas in same report. 
23.  New Menu Options for Exporting Views and Results I.E - Excel 2007+ and PowerPoint 2007+
24.  SQL Results prompt option -If you are working with double columns, you can now write the SQL statement so that filtering is done on code values rather than display values
25.  New View type i.e. - performance tile in 11.1.1.7
26.  To install OBIEE 11g, You Must have to install database and RCU. 
27.  Recommended Visualizations Feature for Creating Views

OBIEE - 10g 
1.    32 Bit
2.    Server Name - OC4J - Oracle Containers for J2EE
3.    Repository and configuration Upload is done in NQSConfig.ini
4.    User, Group and Application role are created in Repository
5.    Integration with other application like SAP or other CRM tool it was not easy. Easy integration with only Siebel CRM
6.    Two Time Series function - Ago and Todate.
7.    Dimension Hierarchies - only you can do Level-Based Hierarchy
8.    No Repository password protection 
9.    RPD has a no password. There was no protection for RPD
10.  KPI and Scorecard was not introduces in OBIEE 10
11.  REQUESTS have been renamed to ANALYSIS in 11g 
12.  IBOTS have been renamed to AGENT in 11g
13.  CHARTS have been renamed to GRAPHS in 11g 
14.  Presentation columns have been renamed to attribute columns in 11g
15.  10g does not support Ragged & Skip Level Hierarchy
16.  Column selector in 10g can be defined just one column
17.  No Option to create custom print layout for dashboard page.
18.  No Breadcrumbs option

Can i use an OLTP backend database for creating a dashboard?
Technically you can use OBIEE with OLTP as well. However real world scenarios pertaining to OLTP makes it difficult for OBIEE to create Star schema from OLTP. Also OBIEE is an engine to perform analytics queries, while in most cases queries generated against OLTP schemas are operational in nature. Better option is to use BI publisher and do away with OBIEE when querying against OLTP.
OBIEE works with any database if you force to do. If you want to follow best practices, its recommended to use with OLAP systems. After all OBIEE is analytics reporting tool and OLAP databases were designed for reporting requirements. So its always advised use the OLAP to get better performance and better analytics from OBIEE.

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.

Define repository in terms of OBIEE?
Repository stores the Meta data information. The extension of the repository file is “.rpd”.   With OBIEE Server, all the rules needed for security, data modeling, aggregate navigation, caching, and connectivity is stored in metadata repositories. Each metadata repository can store multiple business models. OBIEE Server can access multiple repositories                        
Repository is divided into three layers,
1. Physical –    Represents the data Sources
2. Business –   models the Data sources into Facts and Dimension and applies business logic.
(BMM Layer- Business Model & Mapping Layer)
3. Presentation – Specifies the user’s view of the data rendered in OBIEE answers client

What is the end to end life cycle of OBIEE?
OBIEE life cycle:
1. Gather Business Requirements
2. Identify source systems
3. Design ETL to load data to the Data Warehouse
4. Build a repository
5. Build dashboards and reports
6. Define security (LDAP or External table)
7. Based on performance, decide on aggregations and/or caching mechanism.
8. Testing and QA.

Active Directory is a database based system that provides authentication, directory, policy, and other services in a Windows environment
LDAP (Lightweight Directory Access Protocol) is an application protocol for querying and modifying items in directory service providers like Active Directory, which supports a form of LDAP.
What is an Ad Hoc Query?
Ad hoc query means the query that we normally write in query editor
For example in toad
if you write like...select count(*) from w_employee_d...it means it's an ad hoc query.
Ad-hoc means anything...it's not planned.

It's like a partition. Let say we have fact or dimensional data in one or more different tables or data is splited in different data sources. Then each logical table source represents one data segment.
The term Fragmentation is more an OBIEE term whereas the term partitioning refers more to the database side of the same coin. Depending of a value of column, you can split the query against a table or another. Very often, the tables are fragmented according to the most important dimension in a star schema the time dimension.
This functionality is also available in the database and it’s a better way to implement it in the database rather than in OBIEE. Why?
First, because it’s really the job of a database to optimize the performance of a SQL statement. If you go through the Oracle Database Optimizer (the motor of the database), you will see that it has more and more way to do it.
Second because all data access tool will benefit of this functionality transparently.
The goal is simple, it’s :
·         to reduce the I/O (disk) effort
·         to increase the selectivity to increase at the end the performance.
We use fragmentation when we have fact or dimensional data in one or more different tables or data issplitted in different data sources. Then each logical table source represents one data segment.
For example, clients, in the first table are clients from A to M, in the second from M to Z.
How do you create a business model when you have only one source table in Physical layer?
This is very much possible and feasible. It’s called as Single Table model. Good example is SA System Subject Area where we just have a single physical source. No need to create Alias in Physical. Simply use the same table twice in BMM with one Logical Table as Dummy Fact. Like say Count of Users (aggregated). Then apply normal Complex join in BMM and present in presentation layer.

Differences B/w Chronological Key and Logical Key
Chronological key is the key which uniquely identifies the data at particular level. Chronological key is mostly used in time dimensions where time series functions are used.

Where as logical key is the key which is used to define the unique elements in each logical level. A logical level may have more than one level key. When that is the case, specify the key that is the primary key of that level. It is used to specify the column which is used for drill down and which is used as primary keys.

Components of BIEE
Oracle BI (Business Intelligence) consist of following components
i) BI Server- maintains logical data model in local proprietary file (.rpd).
ii) BI Presentation Service – provide framework and interface for presentation of BI data to web clients.
iii) BI Publisher – generates enterprise reports
iv) BI Scheduler - scheduling reports to be delivered to user at specified time
v)  BI Java host- provide services to presentation services for charts, PDFs and Gauges
vi) BI Presentation Service plug-in – entry point for web clients to presentation service requests.

An event polling table (S_NQ_EPT) is a way to notify the Oracle BI Server that one or more physical tables have been updated. Each row that is added to an event table describes a single update event. The cache system reads rows from, or polls, the event table, extracts the physical table information from the rows, and purges cache entries that reference those physical tables.
Finally it truncate the Event Table (S_NQ_EPT)

What is connection pool and how many connection pools did you have in your last project?
Connection pool is needed for every physical database.
It contains information about the connection to the database, not the database itself.
Can use either shared user accounts or can use pass-through accounts we can have multiple connection pools for each group to avoid waiting

What is the purpose of Alias Tables?
An Alias table is a physical table with the type of Alias. It is a reference to a physical table, and inherits all its column definitions and some properties from the physical table. A logical table source shows how the logical objects are mapped to the physical layer and can be mapped to physical tables, stored procedures and select statements. An alias table can be a reference to any of these logical table source types.
          Alias Tables can be an important part of designing a physical layer. The following is a list of the main reasons to create an alias table:
1. To reuse an existing table more than once in your physical layer (without having to import it several times)
2. To set up multiple alias tables, each with different keys, names, or joins
3. To help you design sophisticated star or snowflake structures in the business model layer. Alias tables are critical in the process of converting ER Schemas to Dimensional Schemas.

How do you define the relationship between facts and dimensions in BMM layer?
Using complex join we can define relationship between facts and dimensions in BMM layer.

Did you create any new logical column in BMM layer, how?
Yes. We can create new logical column in BMM layer.
Example: Right click on fact table> select new logical column>give name for new logical column like Total cost.                                                                                                    

Can you use physical join in BMM layer?
Yes we can use physical join in BMM layer.

Can you use outer join in BMM layer?
Yes we can. When we are doing complex join in BMM layer in the join properties we have an option to change the type of join to left outer, right outer, full outer or inner.

What is level based metrics?
Level based metrics means, having a measure pinned at a certain level of the dimension.         
A LBM is a metric that is defined for a specific level or intersection of levels.
Monthly Total Sales or Quarterly Sales are the examples.                                                   

Ex: if you have a measure called “Dollars”, you can create a “Level Based Measure” called “Yearly Dollars” which is Dollars for a Year. This measure will always return the value for the year even if you drill down to a lower level like quarter, month, etc. To create a level based measure, create a new logical column based on the original measure (like Dollars 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 Year in Time Dim.

What is logging level? Where can you set logging levels?
You can enable logging level for individual users.
We can set the logging level based on the amount of logging you want to do. In normal operations, logging is generally disabled (the logging level is set to 0). If you decide to enable logging, choose a logging level of 1 or 2. These two levels are designed for use by Siebel Analytics Server administrators.
Set Logging Level:
1. In the Administration Tool, select Manage > Identity.
2. The Identity Manager dialog box appears.
3. Double-click the user’s user ID.
4. The User dialog box appears.
5. Set the logging level by clicking the up or down arrows next to the Logging Level field

What are different types of variables? Explain each.
There are two classes of variables:
1. Repository variables
2. Session variables

Repository variables-
A repository variable persists from the time the repository is started.
Static: This value does not change until a Siebel Analytics Server administrator decides to change it.
Dynamic: The values of these variables change with the values returned by queries. These variables are linked to an initialization block. An initialization block contains a SQL query. When the repository is started the value returned by the query in the initialization block will be assigned to the dynamic variable.

Session Variables-
Session variables are created and assigned a value when each user logs on (when a new session is started).
There are two types of session variables:
1. System: System variables have reserved names, which cannot be used for other kinds of variables (such as static or dynamic repository variables, or for non-system session variables). 
Ex: To filter a column on the value of the variable LOGLEVEL set the filter to the Variable NQ_SESSION.LOGLEVEL.

2. Non-system: A common use of non-system variables is for setting user filters.                    
Ex: you could define a non-system variable called ‘SalesRegion’ that would be initialized to the name of the user’s sales region. You could then set a security filter for all members of a group that would allow them to see only data pertinent to their region. For example, to filter a column on the value of the variable ‘SalesRegion’ set the filter to the Variable NQ_SESSION.SalesRegion.

What is Authentication? How many types of authentication do we have in OBIEE?
Authentication is the process by which a system verifies a user with the help of a user ID and password. It checks if user has the necessary permissions and authorizations to log in and access data.
There are 4 main types of Authentication in OBIEE:
Operating system authentication
External table authentication
Database authentication
LDAP authentication

What is object level security?
There are two types of object level security: Repository level and Web level
Repository level: In presentation layer we can set Repository level security by giving permission or deny permission to users/groups to see particular table or column.
Web level: this provides security for objects stored in the OBIEE web catalog, such as dashboards, dashboards pages, folder, and reports you can only view the objects for which you are authorized.
For example, a mid-level manager may not be granted access to a dashboard containing summary information for an entire department.

What is data level security?
This controls the type or amount of data that you can see in a report. When multiple users run the same report the results that are returned to each depend on their access rights and roles in the organization. For example a sales vice president sees results for all regions, while a sales representative for a particular region sees data for that region.

What is the difference between Data Level Security and Object Level Security?
Data level security controls the type and amount of data that you can see in a report. Object level security provides security for objects stored in the OBIEE web catalog like dashboards, dashboards pages, folder and reports.

How do you implement security using External Tables and LDAP?
          Instead of storing user IDs and passwords in an OBIEE Server repository, you can maintain lists of users and their passwords in an external database table and use this table for authentication purposes. The external database table contains user IDs and passwords, and could contain other information, including group membership and display names used for Siebel Analytics Web users.
          Instead of storing user IDs and passwords in an OBIEE Server repository, you can have the OBIEE Server pass the user ID and password entered by the user to an LDAP (Lightweight Directory Access Protocol) server for authentication. The server uses clear text passwords in LDAP authentication. Make sure your LDAP servers are set up to allow this.

If you have 2 fact and you want to do report on one with quarter level and the other with month level how do you do that with just one time dimension?
Using level base metrics.

If you want to create new logical column where will you create (in repository or dashboard) why?
It would be better if we create a new logical column in repository because if it is in repository you can use it for any report. If you create new logical column in dashboard then it is going to affect only those reports which are on that dashboard. We cannot use that new logical column for other dashboards.

What is complex join, and where it is used?                                                    
To join a dimension table and fact table in BMM layer we use a complex join.

If you want to limit the users by the certain region to access only certain data, what would you do?
Using data level security.
In the Admin tool: go to Manage -> Identity in left hand pane u will find the user, groups, LDAP server, Hierarchy
What you can do is select the user and right click and go to properties, you will find two tabs named as users and logon, go to user tab and click at permission button in front of user name you have selected as soon as u click at permission you will get a new window with user group permission having three tabs named as general ,query limits and filter and you can specify your condition at filter tab, in which you can select presentation table ,presentation columns ,logical table and logical columns where you can apply the condition according to your requirement for the selected user or groups.

If there are 100 users accessing data, and you want to know the logging details of all the users, where can you find that?
Set the user’s logging level
1. In the Administration Tool, select Manage > Identity.
The Identity Manager dialog box appears.
2. Double-click the user’s user ID. The User dialog box appears.
3. Set the logging level by clicking the Up or Down arrows next to the Logging Level field

How do implement event polling table?
In OBIEE Server event polling tables store information about updates in the underlying databases. These tables are used for cache management. An application that loads data into a data mart could be configured to add rows to an event polling table each time a database table is updated. The Analytics server polls this table at set intervals and invalidates cache entries corresponding to the updated tables.

Define pipeline. Did you use it in your projects?
Yes, pipelines are the stages in a particular transaction, assessment, finance, etc.

How do you work in a multi user environment? What are the steps?
Create a shared directory on the network for Multi-user Development (MUD).
Open the rpd to use in MUD. From Tools->Options, setup the MUD directory to point to the above directory.
Define projects within the rpd to allow multiple users to develop within their subject area or Facts.
Save and move the rpd to the shared directory setup in point 1.
When users work in the MUD mode, they open the admin tool and start with
MUD ->Checkout to check-out the project they need to work on (not use the File open as you would usually do).
After completing the development, users check-in the changes back to the network and merge the changes.

Can you bypass siebel analytics server security? if so how?
Yes we can by-pass by setting authentication type in NQSCONFIG file in the security section as: authentication_type = bypass_nqs.instanceconfig.xml.

What are the things you can do in the BMM layer?
We apply the business login in the BMM layer like creating new logical columns, Aggregation navigation, level based metrics, time series wizard, complex join.

Count (1) and count (*) there is no difference
SELECT count(*) FROM departments ;--- 27
  select count(1) from  departments;--- 27

 SELECT cOUNT(manager_id) FROM departments ; ------ 11
COUNT(*) will return the count of all rows covered by the query whereas
COUNT(columnname) will not count NULL values of that specific column.

How do you know which report is hitting which table, either the fact table or the aggregate table?
After running the report, go to “Administration” tab and go to click on “Manage Sessions”. There you can find the queries that are run and in the “View Log” option in the Session Management you can find which report is hitting which table.

Suppose I have report which is running for about 3 minutes typically. What is the first step you take to improve the performance of the query?
Find the SQL query of the report in Admin->manage Session-> view log then run the SQL query on toad if it takes the same time even in TOAD then modify the query to reduce the query time. If the query runs normally in TOAD then we need to make changes in the repository.

What is aggregate navigation? How do you configure the Aggregate tables in OBIEE?
Aggregate tables store pre-computed results, which are measures that have been aggregated (typically summed) over a set of dimensional attributes. Using aggregate tables is a very popular technique for speeding up query response times in decision support systems.
Ex: If you observe that most of the queries are fired on aggregated values like yearly or monthly data rather that day level data then to speed up the report we can create an aggregate table containing month level and year level data and map it to the respective logical table and set the aggregation levels in the content tab of LTS.

We have 4 dimension tables, in that 2 tables need to have hierarchies then in such a case is it mandatory to create hierarchies for all the dimension tables?
No, it is not mandatory to define hierarchies to other Dimension tables.

Can you have multiple data sources in OBIEE?
Yes, we can have multiple data sources of different types.

Do you know about Initialization Blocks? Can you give me an example where you used them?
Initialization blocks are used for instantiating the value of a variable.
To create dynamic variable you have to create IB to write SQL statement. The result of the query would be assigned as value to the variable.

What is query repository tool?
It is utility of OBIEE Admin tool
It allows you to examine the repository metadata
Examine relationship between metadata objects like which column in the presentation layer maps to which table in physical layer                                                                                
Ex: we can search for objects based on name, type.

Can you migrate the presentation layer to a different server.
No, we cannot migrate only one particular layer to another server, we have to migrate the complete repository or the web catalog.

How do you identify what are the dimension tables and how do you decide them during the Business/Data modeling?
Dimension tables contain descriptions that data analysts use as they query the database.           Ex: the Product table contains product packaging information; and the Period table contains month, quarter, and year values. The tables which contain numeric values used for calculations are used as Fact tables.

Why do we have multiple LTS in BMM layer? What is the purpose?
To improve the performance and query response time.

How do i disable cache for only 2 particular tables?
In the physical layer, double click on a table on the general tab we have an option Cachable we can either enable it or disable it for that particular table.

How do you split a table in the rpd given the condition. ( the condition given was Broker and customer in the same table) Split Broker and customer.
We need to create alias tables in the physical layer and use which ever columns are required.

What are the major components in the OBIEE architecture?
a. Client
b. Presentation services (along with cache)
c. Repository
d. Database connection
e. Enterprise data warehouse
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)
The folder names may change with the OBIEE 11g.

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)

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

What is time series wizard? When and how do you use it?
o We can do comparison for certain measures ( revenue.,sales etc.. ) for current year vs previous year, we can do for month or week and day also
o Identify the time periods need to be compared and then period table keys to the previous time period.
o The period table needs to contain a column that will contain “Year Ago” information.
o The fact tables needs to have year ago totals.
o To use the “Time series wizard”. After creating your business model right click the business model and click on “Time Series Wizard”.
o The Time Series Wizard prompts you to create names for the comparison measures that it adds to the business model.
o The Time Series Wizard prompts you to select the period table used for the comparison measures
o Select the column in the period table that provides the key to the comparison period. This column would be the column containing “Year Ago” information in the period table.
o Select the measures you want to compare and then Select the calculations you want to generate. For ex: Measure: Total Dollars and calculations are Change and Percent change.
o Once the Time series wizard is run the output will be:
a) Aliases for the fact tables (in the physical layer)
b) Joins between period table and alias fact tables
c) Comparison measures
d) Logical table sources
o In the General tab of the Logical table source etc you can find “Generated by Time Series Wizard” in the description section
o Then you can add these comparision measures to the presentation layer for your reports.
o Ex: Total sales of current qtrvs previous qtrvs same qtr year ago

What are other ways of improving summary query reports other than Aggregate Navigation and Cache Management
” Indexes
” Join algorithm
” Mat/view query rewrite
” Web proper report design its optimal by making sure that it is not getting any addition column or rows

What is query repository tool?
o It is utility of Seibel/OBIEE Admin tool
o allows you to examine the repository metadata tool
o for example: search for objects based on name,type.
o Examine relationship between metadata objects like which column in the presentation layer maps to which table in physical layer

What is JDK and why do we need it?
o Java Development Kit (JDK), A software package that contains the minimal set of tools needed to write, compile, debug, and run Java applets.

Oracle doesn’t recommend Opaque Views because of performance considerations, so why/when do we use them?
o an opaque view is a physical layer table that consists of select statement. an opaque view should be used only if there is no other solution.

Can you migrate the presentation layer to a different server.
o No we have to migrate the whole web & rpd files

Why do we have multiple LTS in BMM layer?What is the purpose?
o to improve the performance and query response time.

What is the full form of rpd?
o there is no full form for rpd as such, it is just a repository file (Rapidfile Database)

How do i disable cache for only 2 particular tables?
o in the physical layer, right click on the table there we will have the option which says cacheable

How do you split a table in the rpd given the condition.( the condition given was Broker and customer in the same table) Split Broker and customer.
o we need to make an alias table in the physical layer.

What type of protocol did you use in SAS?
o TCP/IP

How many repository files can be loaded to a BI Server simultaneously? Assume its a single server with single instance of BI Server running just to keep things
BI Server only can handle one repository file in online mode.

1. How many tables are needed in minimum to pass through the Consistency Checking in Logical Layer (Business Mapping and Modeling Layer) of the repository?
One dimension and one fact is enough for BMM

2. Can you use an OLTP backend database for creating a dashboard?
Yes, it’s nothing but transactional data.

3. Does OBIEE store physical sql? How is physical sql generated in OBIEE environments?
Yes it stores check in your manage sessions or Nqquery.log..........its normal SQL 

Can i use an OLTP backend database for creating a dashboard?
Technically you can use OBIEE with OLTP as well. However real world scenarios pertaining to OLTP makes it difficult for OBIEE to create Star schema from OLTP. Also OBIEE is an engine to perform analytics queries, while in most cases queries generated against OLTP schemas are operational in nature. Better option is to use BI publisher and do away with OBIEE when querying against OLTP.
OBIEE works with any database if you force to do. If you want to follow best practices, its recommended to use with OLAP systems. After all OBIEE is analytics reporting tool and OLAP databases were designed for reporting requirements. So its always advised use the OLAP to get better performance and better analytics from OBIEE.

No comments:

Post a Comment

Big Data FQA

1) What is a Big Data Architecture? Generally speaking, a Big Data Architecture is one which involves the storing and processing of data...