The 11 Configuration Options Added in SQL Server 2022, and Their Documentation
I checked the 11 SQL Server 2022 configuration options added after SQL Server 2019 against sys.configurations and Microsoft Learn.
I Could Not Find Documentation for Most of What SQL Server 2022 Added
I diffed the SQL Server 2019 and 2022 system catalogs over the DAC and checked 558 new objects against Microsoft Learn. I found no documentation for 477.
INTERSECT and EXCEPT: Where NULL Finally Behaves
INTERSECT and EXCEPT treat NULL as equal, the one place NULL comparison behaves as expected. Use them for NULL-safe row comparison.
One NULL in a Unique Key, and None Across a Join
A UNIQUE constraint allows one NULL but rejects a second, and an equi-join drops NULL keys. Filtered indexes and NULL-safe joins.
ISNULL vs COALESCE: Not as Interchangeable as They Look
ISNULL and COALESCE differ on result type, truncation, nullability, and how often they evaluate their input. When to use each.
One NULL Turns the Whole Concatenation Into NULL
With +, one NULL operand makes the whole concatenation NULL and a built-up label vanishes. Use CONCAT, COALESCE, or CONCAT_WS instead.