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...
Pentaho Data Integration(PDI)
Pentaho Data Integration(PDI) is the most powerful open source ETL tool available in market. It is one of the important tools available in Pentaho BI...
Slowly Changing Dimension SCD
In Data Warehouse, problem of slowly changing dimension is a common one. This applies to cases where the attribute for a record varies over time. Today...
SQL – Drop Table
SQL – Drop Table is DDL (Data definition language) statement.The Drop Table command is used to delete table from database. Drop Table Statement : Removes named table...
SQL – Alter Table
SQL – Alter Table is DDL (Data definition language) statement.The ALTER TABLE command is used to modify the definition (structure) of a table by modifying the...
SQL – Create Table
Create Table is a DDL (Data definition language) statement. The CREATE TABLE is used to create and define a new relational table. CREATE TABLE Statement :...
Types Of Fact
Till now, we have already discussed about types of dimension. So lets move to another concept in dimensional modelling, i.e, FACT . A fact is a...
Types of Dimension
Dimensional modelling has two basic concepts – fact and dimension. Dimensions store the textual descriptions of the business attribute. Without the dimensions, we cannot measure...
Dimensional Modeling
I have discussed about the Data Modeling in my previous article – What is Data Modeling ? . I know most of you will be...