Raise a compatibility level safely by capturing a Query Store baseline, changing one database, comparing plans, and keeping a tested reversal.
sys.objects, sys.all_objects and sys.system_objects
Compare sys.objects, sys.all_objects and sys.system_objects to find SQL Server user objects, system objects, and metadata visibility gaps.
SQL SERVER – Get Query Plan Along with Query Text and Execution Count
A handy script that shows each query’s text, its execution count and its query plan, so you can see what runs most often on your server.
Joining Two History Tables at a Point in Time With FOR SYSTEM_TIME AS OF
Use FOR SYSTEM_TIME AS OF to join temporal tables at one UTC instant, compare range forms, and index the history lookup correctly.
Evaluating a New SQL Server Version in One Week
Evaluating a New SQL Server Version in one week works when you install, restore, run a real workload, compare results, and write a decision.
SQL SERVER – Introduction to Change Data Capture (CDC) in SQL Server 2008
My first article on Simple-Talk introduces Change Data Capture in SQL Server 2008, which records INSERTs, UPDATEs and DELETEs in simple relational change tables.
SUM DISTINCT: Equal Amounts Are Not Duplicate Rows
SUM DISTINCT totals different amounts without checking order identity. I’d establish the row grain first. Compare equal-priced orders, repeated copies and missing amounts.