CASE is SQL’s answer to other programming languages IF-ELSE statement. If you need to test a condition and return a value CASE is the expression you need.
SQL Server Window Functions are incredibly powerful and allow us to access a total from another row and bucket data to show top performers.
SQL window functions are incredibly powerful and allow us to see the rows in a table with a new column showing a running total, rank or moving average.
Aggregate functions bring your data to life.
They allow you to take a standard table and use a function or two to build metrics and answer questions about the data.
Your database doesn’t just contain your data. It also contains data about your data.
A high-level overview of why your DBA needs to VACUUM your tables