Build a retention grid from raw orders with five rows you can check by eye. Includes the DISTINCT rule and why unfinished months show NULL.
What Is a Star Schema?
A star schema is one fact table surrounded by dimension tables. What facts and dimensions hold, why grain is the decision you cannot undo, why the data repeats on purpose, and a worked example in AdventureWorksDW.
Designing a Date Dimension
A date dimension makes reporting calendars explicit with fiscal periods, holidays, weekdays, and a repeatable SQL Server build script.
SQL SERVER – Step by Step Guide to Beginning Data Quality Services in SQL Server 2012 – Introduction to DQS
A step by step introduction to Data Quality Services in SQL Server 2012 for beginners: build a Knowledge Base from an Excel file and use it to spot bad data.
Slowly Changing Dimension Quiz: Type 1 or Type 2?
This Slowly Changing Dimension Quiz asks which type to use when a customer moves from Denver to Austin and sales before the move must stay under Denver. The answer is Type 2. A tested script runs Type 1 and Type 2 side by side, checks the move date and shows both reports.
SSAS Tabular vs Multidimensional: Choosing for a New Project
Compare Tabular vs Multidimensional for SSAS projects, including storage, relationships, write-back, team skills, and model checks.
Surrogate Keys and Natural Keys
Surrogate keys keep warehouse history stable while natural keys preserve source identity; learn lookup, uniqueness, and change handling.