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.
Find Memory Used by Each Database in SQL Server
To see the memory used by each database, count its pages in the buffer pool with sys.dm_os_buffer_descriptors. This post builds a small demo database, shows buffer and dirty page sizes before and after a checkpoint, explains the row with no name, and covers what the buffer pool numbers leave out, such as the plan cache.
SQL SERVER – How to Know Transaction Isolation Level for Each Session?
An outsourced app had teams using different coding standards, and performance suffered. Here is how to find the transaction isolation level of each session.
The Tipping Point: Why SQL Server Skips Your Nonclustered Index
Find the tipping point where key lookups cost more than a scan, then compare covering and filtered indexes with measured reads.






