1) What is ETL?
Ans : In datawarehousing architechture, ETL is an important component, which manages the data for any business process. ETL stands for Extract, Transform and Load. Extract does the process of reading data from a database. Transform does the converting of data into a format that could be appropriate for reporting and analysis. While, load does the process of writing the data into the target database.
2) Explain what are the ETL testing operations includes?
Ans : ETL testing includes
Ans : The types of data warehouse applications are
4) What are the various tools used in ETL?
Ans :It is a central component of a multi-dimensional model which contains the measures to be analysed. Facts are related to dimensions.
Types of facts are:
Ans :Cubes are data processing units comprised of fact tables and dimensions from the data warehouse. It provides multi-dimensional analysis.OLAP stands for Online Analytics Processing, and OLAP cube stores large data in muti-dimensional form for reporting purposes. It consists of facts called as measures categorized by dimensions.
7) Explain what is tracing level and what are the types?
Ans :Tracing level is the amount of data stored in the log files. Tracing level can be classified in two Normal and Verbose. Normal level explains the tracing level in a detailed manner while verbose explains the tracing levels at each and every row.
8) Explain what is Grain of Fact?
Ans :Grain fact can be defined as the level at which the fact information is stored. It is also known as Fact Granularity
9) Explain what factless fact schema is and what is Measures?
Ans :A fact table without measures is known as Factless fact table. It can view the number of occurring events. For example, it is used to record an event such as employee count in a company.The numeric data based on columns in a fact table is known as Measures
10) Explain what is transformation?
Ans : A transformation is a repository object which generates, modifies or passes data. Transformation are of two types Active and Passive
11) Explain the use of Lookup Transformation?
Ans : The Lookup Transformation is useful for
Ans : To improve performance, transactions are sub divided, this is called as Partitioning. Partioning enables Informatica Server for creationg of multiple connection to various sourcesThe types of partitions are
Ans : The advantage of using the DataReader Destination Adapter is that it populates an ADO recordset (consist of records and columns) in memory and exposes the data from the DataFlow task by implementing the DataReader interface, so that other application can consume the data.
14) Using SSIS ( SQL Server Integration Service) what are the possible ways to update table?
Ans : To update table using SSIS the possible ways are:
Ans : In case if you have non-OLEBD source for the lookup then you have to use Cache to load data and use it as source
16) In what case do you use dynamic cache and static cache in connected and unconnected transformations?
ETL Testing Interview Questions & material
|Selection||File type icon||File name||Description||Size||Revision||Time||User|