SQL Server 2022 (16.x) and Later · All Editions · Facts Verified from Microsoft Learn Every fact in this article is sourced directly from Microsoft Learn documentation. Nothing is guessed, inferred from community posts, or carried over f...
By Huy Vũ
SQL Server’s Query Store is the closest thing the engine has to a flight data recorder. Before Query Store existed, when a query suddenly became slow there was often no evidence to work with. The execution plan that caused the problem wa...
By Huy Vũ
SQL Server’s automatic statistics update feature is designed to keep the query optimizer’s cardinality estimates accurate as data changes. When it works, it is invisible. When it silently fails, the optimizer continues making execution p...
By Huy Vũ
About three years ago, SQL Server 2022 introduced Parameter-Sensitive Plan Optimization (PSPO). At the time, I explained that it didn’t work particularly well, and went so far as to pronounce PSPO in a rather unflattering way. I wouldn’t...
By Huy Vũ
Hi. I’m a former developer who’s moved into database administration, and here’s what I wish somebody would have told me when I got started. 7. SQL functions rarely perform well. Good developers like to reuse code by putting it into funct...
By Huy Vũ
Normally when we think about parameter sniffing, we think about a tiny data vs big data problem: the tiny data’s plan goes in first, and when we try to process big data, performance is terrible. But sometimes, it’s the exact opposite. I’...
By Huy Vũ