How do you sum values for each group without GROUP BY and still keep every row? Here is how SUM with OVER and PARTITION BY answers a reader’s question.
Optimal Value for Max Worker Threads in SQL Server
The optimal value for Max Worker Threads is the default, 0, which tells SQL Server to calculate the limit from the number of logical processors. This post shows how to read the real limit, how the formula works, and which wait and queue counters prove a thread shortage before you change anything.
SQL SERVER – How to DELETE Multiple Table Together Via SQL Server Management Studio (SSMS)?
A DBA asked for a shortcut to drop more than one table at once in SSMS without writing T-SQL. Here are the simple steps, using just the keyboard.
SQL SERVER – Performance Comparison IN vs OR
Which query runs faster, one with IN or one with OR? Here is my performance comparison IN vs OR on AdventureWorks, and both turn out equal.
DATE_CORRELATION_OPTIMIZATION: Helping Joins on Related Dates
SQL Server can learn that an order date and a ship date move together. Here is a small demo of the read savings and the trade you accept.
SQL SERVER – How to Fix CONVERT_IMPLICIT Warnings?
CONVERT_IMPLICIT warnings are one of the most common performance issues I find in health checks. Here is how to find them in your queries and how to fix them.
How to Find Cardinality or Uniqueness for any Column? – Interview Question of the Week #177
What is Cardinality, and how do you find it for a column? This simple script shows the percentage of unique values, using an AdventureWorks table.