September 24, 2018

Sreekanth B

VMWare Pentaho Recently Asked Interview Questions Answers

What Do You Un Derstand By The Term Etl?

It is an entri level tool for data manipulation.

What Do You Understand By Hierarchical Navigation?

A hierarchical navigation menu allows the user to come directly to a section of the site several levels below the top.

What Do You Understand By Three Tier Data Warehouse?

A data warehouse is said to be a three-tier system where a middle system provides usable data in a secure way to end users. Both side of this middle system are the end users and the back-end data stores.

What Is Ods?

ODS is Operational Data Store which comes in between of data warehouse and staging area.

Differentiate Between Etl Tool And Olap Tool?

ETL Tool is used for extracting data from the legecy system and load it into specified database with some processing of cleansing data.

OLAP Tool is used for reporting process . Here data is available in multidimensional model hence we can write simple query to extract data from database.
VMWare Pentaho Recently Asked Interview Questions Answers
VMWare Pentaho Recently Asked Interview Questions Answers

Wha Is Xml?

XML is an extensiable markup language which defines a set of rule for encoding documents in both formats which is human readable and machine readable.

What Are Various Tools In Etl?

Abinitio,DataStage, Informatica, Cognos Decision Stream, etc

Define Mdx?

MDX is multi- dimensional expression which is a main query language implemented by the Mondrains.

Define Multi-dimensional Cube?

It is a cube to view data where we can slice and dice the data. It have time dimension, locations and figures.

How To Perform Database Join With Pdi (pentaho Data Integration)?

PDI supports joining of two tables form the same databse using a ‘Table Input’ method, performing the join in SQL only.

On the other hand, for joining two tables in different databases, users implement ‘Database Join’ step. However, in database join, each input row query executes on the target system from the main stream, resulting in lower performance as the number of queries implement on the B increases.

To avoid the above situation, there is yet another option to join rows form two different Table Input steps. You can use ‘Merge Join ‘step, using the SQL query having ‘ORDER BY’ clause. Remember, the rows must be perfectly sorted before implementing merge join.


Explain How To Sequentialize Transformations?

Since PDI transformations support parallel execution of all the steps/operations, it is impossible to sequentialize transformations in Pentaho. Moreover, to make this happen, users need to change the core architecture, which will actually result in slow processing.

What Is Mdx And Its Usage?

MDX is an acronym for ‘Multi-Dimensional Expressions,’ the standard query language introduced by Microsoft SQL OLAP Services. MDX is an imperative part of XML for analysis API, which has a different structure than SQL.

A basic MDX query is:

SELECT {[Quantity].[Unit Sales], [Quantity].[Store Sales]} ON COLUMNS,

{[Product].members} ON ROWS

FROM [Sales]

WHERE [Time].[1999].[Q2]

Define Three Major Types Of Data Integration Jobs.?

Transformation Jobs : Used for preparing data and used only when the there is no change in data until transforming of data job is finished.

Provisioning Jobs : Used for transmission/transfer of large volumes of data. Used only when no change is data is allowed unless job transformation and on large provisioning requirement.

Hybrid Jobs : Execute both transformation and provisioning jobs. No limitations for data changes; it can be updates regardless of success/failure. The transforming and provisioning requirements are not large in this case.


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