Very Very important Video For Interview Part 1 SQL INTERVIEW QUESTIONS FOR DATA ANALYST|SQL INTERVIEW QUESTIONS FOR BUSINESS ANALYST| SQL QUESTIONS Part 2 SQL INTERVIEW QUESTIONS PART 2 |SQL INTERVIEW QUESTIONS FOR DATA/BUSINESS ANALYST| SQL QUESTIONS Q. What are SCD’s ? Q. Difference between SCD1, SCD2, SCD3. Tech Coach Channel Ans----- A Slowly Changing Dimension (SCD) is a dimension that stores and manages both current and historical data over time in a data warehouse. The ‘Slowly Changing Dimension’ problem is a common one particular to data warehousing. This applies to cases where the attribute for a record varies over time. There are three types of SCD (SCD1,SCD2,SCD3) SCD1- Overwrite SCD2 - Append SCD3 - Update Advantages Disadvantages When To Use SCD1 This is the easiest way to handle the SCD problem, since there is no need to keep track of old information. All history is lost. By applying this methodology, it is not possible to trace back in history. Should be used when it is ...