ETL Testing Guide
Data Warehouse Concepts. Introduction – ETL Testing. ETL Development Life Cycle. ETL Testing Life Cycle. Test Strategies for ETL Testing.
Category: ETL Testing
Surrogate key In Data warehouse.
Defining Surrogate Key : Surrogate Key may be defined as a system generated key which is used to maintain unique records in the Data warehouse databases. Need for Surrogate key : We all know...
Slow Changing Dimensions in Informatica (SCD)
Defining Slow Changing Dimensions: Change in the city names for e.g. Madras to Chennai , Change in the price of the product , Changes in the residential location of the people , Changes in...
DUAL Table in Oracle
Defining Dual Table : DUAL is a Special table having one row and one column. The Datatype of the Column is Varchar2(1) , Column Name is ‘DUMMY’ and Value is ‘X’. It is created...
Set Operators
Defining Set Operators: Set Operators combine the Result Set of two or more SELECT queries into a single result. The query containing the set operator is called Complex Query. Key Facts about Set Operators...
Joins in SQL
What are Joins ? Joins may be defined as SQL queries, which are used to combine rows from two or more tables or views based on the relationship between the tables. Why and When...
Correlated Sub Queries.
Unlike the normal Subqueries, the Correlated Subqueries can also be defined as Inner Query embedded in an Outer Query. But the main difference between Correlated and Uncorrelated or normal Subquery is –
Sub Queries [ Uncorrelated Sub Queries ]
A Subquery as the name suggests , is an Inner Query nested or embedded within another SQL Query also called Outer Query. Key Facts about Sub Queries. The Inner Query or the Subquery...
Views
Understanding Views: To understand views let’s take an e.g. of a mirror from our day to day life. We can see exact replica of ourselves in the mirror i.e. Virtual image. View is a also...