Classico
In the bad old days, which are still your days (but at least you have better days to look forward to), SQL Server’s cost-based optimizer would take a parametrized query, come up with a query plan, and then reuse …
Category: SQL Server 2022
SQL Server 2022 Parameter Sensitive Plan Optimization: The Problem With Sniffed Parameter Sensitivity
Long Time Coming
When Microsoft first started coming up with these Intelligent Query Processing features, I think everyone who cares about That Sort Of Thing© wondered when parameter sensitivity would get fixed.
Let’s take a brief moment to talk about …
SQL Server 2022: Cardinality Estimation Feedback
Quiet As Kept
I’ve been trying to take the general temperature when it comes to SQL Server 2022. At least from a performance perspective, some interesting things have been introduced so far.
There have been a few neat things:
- Parameter
What’s The Point Of DOP Feedback In SQL Server 2022?
Loud Engine
If you’re ever on a long flight and want something to fall asleep to, ask a DBA how to set MAXDOP.
Sometimes I even ask myself that question when I’m tossing and turning at night.
There are a …
SQL Server 2022 Finally Adds Actual Non Parallel Plan Reasons To Query Plans
Wayback Machine
SQL Server query plans have had, forever, pretty generic reasons embedded in the XML for why your query was prevented from going parallel.
Not for things like it not breaking the Cost Threshold For Parallelism barrier, which should …
Some Thoughts On Query Store Hints In SQL Server 2022
Young And Old
Query hints seem to get treated like prescription drugs. You hear all the problems they can solve, but then you get a long list of problems they can cause.
“Your cholesterol will be lower, but you might …
SQL Server 2022 Is Going To Mess Up Your Query Monitoring Scripts
At Least For Now
SQL Server 2022 has a new feature in it to help with parameter sensitive query plans.
That is great. Parameter sensitivity, sometimes just called parameter sniffing, can be a real bear to track down, reproduce, and …
SQL Server 2022: What The Heck Is sp_copy_data_in_batches?
Make It Or Not
I’m gonna be honest with you, dear reader, because without honesty we’ve got nothing.
Except lies — which you know — those can be comforting sometimes. Hm. I’ll have to think about that one for a …
SQL Server 2022: GENERATE_SERIES Causes Parallel Deadlocks In A Transaction
Many Times!
These table valued functions of the built-in variety have this problem.
This one is no exception. Well, it does throw an exception. But you know.
That’s not exceptional.
DROP TABLE IF EXISTS
dbo.select_into;
BEGIN TRAN
SELECT
id =
… SQL Server 2022 GENERATE_SERIES: Some Notes At Release Time
Yep, I know
It’s the first public CTP. Things will change. Things will get better. Think about the rich history of Microsoft fixing stuff immediately, like with adding an ordinal position to STRING_SPLIT.
That came out in SQL Server …