1.
What is Cognos Dynamic Cube? And when to use it?
Dynamic cubes are also referred to as in-memory OLAP
cubes in IBM Cognos, that are used for loading data from structured relational
data sources under a snowflake or star schema directly. The objective of
dynamic cubes is to deliver a quick response to reports and analyse huge
volumes of data. This is available in Cognos 10.2 or higher versions. Dynamic
cubes are used for addressing the difficulty of high performance and low
latency interactive analysis and also for reporting against terabytes of data. Supported
databases are DB2, Netezza, Microsoft SQL Server, Oracle, Teradata databases.
2.
Explain Dynamic Cube Lifecycle in Cognos?
- Model and Publish (Warehouse and CM)
- Deploy and Manage (Dynamic Cube Server,
CM) - Reporting and Analytics (Dynamic cube,
Logs) - Optimize (Warehouse, CM, Logs)
3.
What is Cognos Cube Designer?
Cognos Cube Designer is a modeling tool used for
dynamic cubes and dimensional metadata. The object editors, data source
explorer, the project explorer tree, and properties panes are the essential
elements of the Cognos Cube Designer user interface.
4.
Explain Cognos Cube Designer modeling workflow.
- First model your cube definition in
Cognos Cube Designer - Create Dynamic cube
- Deploy your dynamic cube to BI server
5.
How to administrate Dynamic cube?
Administration tasks included while selecting a cube
to the QueryService Instance are:
- Start/Stop
the Cube - Monitoring
Cube - Managing
the cache - Scheduling
a refresh of the cache
6.
What do you mean by Aggregate Advisor?
Aggregate Advisor is used for the purpose of performance
optimization utility. It can analyze dynamic cubes and suggest aggregates when
needed to improve cube performance. It specifically generates two types of
recommendations.
- In-Memory
Recommendations: This aggregate
recommendation is implemented by the IBM® Cognos® Business Intelligence server
the next time the cube is started and aggregates are saved in the Content
Store.
- In-Database
Recommendations: This aggregate recommendation will be implemented
automatically to the database and the model.
7.
What is a Framework Manager?
For creating a business model of metadata derived
from one or more data sources, we use a Framework Manager. In simple words,
it’s a windows based tool utilised for publishing business models for Cognos in
the form of packages for analytical reporting and analysis purposes.
8.
Describe Cognos Access Manager.
Cognos Access Manager establishes a centralized
environment for defining, storing, and managing security data to IBM Cognos business
information applications.We can set up and manage secure user access to data at
one central location itself. With this, we can even handle user sign on
information and auto access privileges for the servers and data sources
containing necessary data.
9.
Explain about Aggregate Cache.
Two types of pre-computed aggregate values are supported
by Cognos Dynamic Cubes:
1) Stored in-memory aggregate cache
2) Stored in in-database tables (in-database
aggregate)
Aggregate Advisor can suggest a collection of
in-memory aggregate. In-memory aggregate does not require the involvement of
DBA. Recommendations are stored in Content Manager and take effect next time a
cube is started.
10.
What is Cognos ReportNet?
Cognos ReportNet is a web-based business
intelligence suite of reporting applications, which is used for creating and
running reports. It doesn’t require any additional software to access. Just
through a web browser, we can access it. It supports multiple formats such as
PDF, Excel, HTML, XML, and CSV.
The components of ReportNet are the following:
- Cognos
connection - Framework
manager - Report
Studio - Query
Studio
11. What is the difference between Embedded filters and standalone filters?
Both Embedded filters and standalone filters are
supported by the Framework Manager. For the purpose of using only one query
object or dimension in the filter, we use embedded filters. For reusing the
expression, we use standalone filters.
12.
What is DTM?
DTM converts data received from reader buff and
transits transformation to transformation on a row by row basis. Depending on
the requirement, transformation caches are also utilized.
13.
What is Cognos Powerhouse? And why is it used?
Cognos Powerhouse supports high-productivity
application development that enables you to create data-driven business
solutions faster. It supports access for web-based, server/client, and
traditional terminal-based. Powerhouse has huge popularity due to its productivity,
performance, flexibility, and reliability.
14.
Explain Dynamic cube modeling?
In IBM Cognos Dynamic Cubes, we can design and
develop dynamic cubes using IBM Cognos Studios for use as data sources. Following
tasks needs to be processed to create dynamic cubes:
- Build
a Java™ Database Connectivity (JDBC) data source connection to the relational
database in IBM Cognos Administration.
- Import
the metadata from Cognos Cube Designer for modeling dynamic cubes.
- Model
the dimensional metadata and the dynamic cubes.
- Deploy
individual dynamic cubes to the Content Manager as OLAP data sources in IBM
Cognos Analytics.
- Publish
a package that includes a deployed cube.
- Configure
the deployed cube for use as a data source by the Query Service and start the dynamic
cube in IBM Cognos Administration.
15.
What is warehouse cubing?
Warehouse Cubing services provide a multidimensional
view of data collected in a relational database. We can create, import, edit,
export, and deploy cube models across relational warehouse schema using the
cubing services. Optimization techniques are also supported by cubing services
for improving OLAP queries performance.
16.
What is called Cognos Reporting tool?
Cognos is an IBM reporting tool which is used for
reporting and analysis of various data from different datawarehouse.
17.
Mention the difference between ‘macros’ and ‘prompt’?
Macro is used to run set of instructions to execute
the report but prompt provide a way to change the report dynamically.
18.
What is a Cube?
Cube is set to be multi-dimensional view of
dimension and measures and it is used to analyze the data in various forms like
Slicing and Dicing.
19.
What is called Cognos powerplay?
Cognos powerplay is nothing but a multidimensional
on-line analysis of data.
20. What is a Sparse Cube?
A cube in which number of populated cells as a
percentage of total cells is too low
21.
What is the use of advanced windows in Turbo Integrator?
Using the Advanced window you can create your own
custom scripts.
22.
What is the logic of Sparsity in cubes?
On average, the more dimensions a cube has, the
greater the degree of sparsity.
23.
What is Under Feeding?
Failing to feed cells that contain rules-derived
values. This always results in incorrect values and must be avoided at all
costs.
24.
What are FEEDERS?
It creates a placeholder on cells so that cells will
not be skipped during the consolidation
25.
What is FEEDSTRING?
If the rule defines string values for any cells,
then FEEDSTRINGS must be inserted as the first line of rule. FEEDSTRINGS
declaration ensures that cells containing rules-derived strings are fed. Every
calculation statement in a rule should have a corresponding feeder statement.
26.
What are simple FEEDERS?
FEEDERS that are applied to calculation within one
dimension of one cube.
27.
How can we generate cubes in Cognos?
Power
Play Transformer contains dimension, measure, model and cube. There are
different ways to generate a cube.Steps
to be followed:
- Just
right click on the cube name and build. - We
can write scripts in UNIX. Using that we can easily generate the cube
28. What is the use of Cognos
decision stream?
Cognos
decision stream is set to be a tool which is used for extracting, transforming
the data from different data sources to target data source.