Slowly Changing Dimensions – The Ultimate Guide

Do you understand SQL but still cannot write SQL queries correctly ? Are you afraid to switch jobs because of the SQL interview rounds or have you failed SQL Interview earlier ? If you are someone who understands SQL and need more confidence to solve SQL queries correctly, I would like to share my recent online course especially created for you. Check for more details: In this video I have explained what is Slowly Changing Dimension tables. Why do we need it and how do we create it ? We will also talk about Table design consideration for SCD tables and how do we implement SCD-1, SCD-2 & SCD-3 tables using SQL. A Dimension table stores attributes and descriptive details about the measures calculated in the Fact tables. With time it is expected that some changes will happen to these attributes stored in the Dimension tables. Hence the word “Changing“. However those changes may not be very frequent. Thereby adding the word “Slowly“. The Dimension table which is expecting some changes over time is called Slowly Changing Dimension. Link to the blog referred in the video: Video Timeline: 00:00 Introduction 00:50 SCD Definition 01:40 Different Types of SCD - 1,2,3 05:00 SCD Implementation - Table design consideration 10:40 SCD Implementation - SQL Update & Insert 15:15 Day 1 - Staging 15:57 Day 1 - SCD-1 16:39 Day 1 - SCD-2 17:00 Day 1 - SCD-3 18:00 Day 2 - Staging 18:38 Day 2 - SCD-1 19:43 Day 2 - SCD-2 21:55 Day 2 - SCD-3 23:06 Day 3 - Staging 23:24 Day 3 - SCD-1 24:08 Day 3 - SCD-2 25:08 Day 3 - SCD-3 Leave your comments below. Practice SQL questions on Data Lemur platform. I will highly recommend to sign up for this platform. I am sharing my referral link below for easy reference.