Month: October 2017

SQL Index

While executing SQL query, most important aspect to consider is performance.  So  how you achieve a good performance from database queries. Let us take the...

What is Big Data ?

Big Data has been a buzz word for quite some time now and it is catching popularity faster than pretty much anything else in the...

Why Informatica is best ETL tool ?

ETL tools are required to extract, transform and load the data to Data Warehouse. ETL tools are the key to handle the database and Data...

File Types Of Unix

As discussed in the Introdution Of Unix ,a simple description of the UNIX system, is this:“On a UNIX system, everything is a file; if something is not...

Introduction Of Unix

UNIX is a popular operating system  for more than two decades which was first developed in the 1960s, and has been under constant development ever...

WHERE Vs HAVING CLAUSE IN SQL

While working with SQL, one of the question which often creates confusion is whether to use where or having clause.Though it appears that both clauses...

How to Choose Right ETL tool ?

So you planning to build Data Warehouse? But not able to decide which is the right ETL tool for you business.I can understand your confusion...

SQL Interview Questions and Answers

1. What is SQL ? SQL stands for Structured Query Language.It is a database language used for database creation, deletion, fetching rows and modifying rows...

SQL – Select Statement

Select statement is a DML (Data Manipulation Language) statement.The SELECT statement is an SQL statement that specifies which rows and columns to fetch from one...

SQL Join

A SQL Join clause is used to combine rows from two or more tables, views, or materialized views based on a common field between them. A...