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.
SQL SERVER – Upgrade Error – Upgrading Subscription Settings and System Objects in Database [DBName].
A patch failed at “Upgrading subscription settings and system objects in database” with invalid object MSreplication_subscriptions. Here is the fix.
How to Generate Fibonacci Series for the First 1000 Values? – Interview Question of the Week #174
How to generate Fibonacci series for the first 1000 values? Most answers online stop near 70 or 80 values because the numbers get too big. Here is mine.
How an Open Transaction Uses Free Log Space
An open transaction holds free log space hostage. This post runs one transaction in a SIMPLE recovery database and reads the log after the load and after the commit. It explains why the log grows before COMMIT, what ACTIVE_TRANSACTION means, and why a new FULL recovery database behaves like SIMPLE until its first full backup.