What’s New & Undocumented in SQL Server 2019 Cumulative Update 9

SQL Server 2019
26 Comments
Last week’s SQL Server 2019 Cumulative Update 9 snuck in some undocumented things. We got two new DMVs for Always On Availability Groups, sys.dm_hadr_cached_replica_states and sys.dm_hadr_cached_database_replica_states. They have a subset of data from other AG DMVs: I sure wish I could point you to the documentation or KB article on those. But we have no…
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SQL Server 2019 is out…now.

SQL Server 2019
7 Comments
After just one release candidate, Microsoft has decided it’s ready to go, apparently! Well, kinda: the official build in the release notes is 15.0.2000.5, and there’s already a “servicing update” to 15.0.2070.41. I’m not sure I wanna know what’s going on there. Anyhoo, SQL Server 2019 is available for download now. This also means it’s…
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Froid

Finding Froid’s Limits: Testing Inlined User-Defined Functions

This week, I’ve been writing about how SQL Server 2019’s bringing a few new features to mitigate parameter sniffing, but they’re more complex than they appear at first glance: adaptive memory grants, air_quote_actual plans, and adaptive joins. Today, let’s talk about another common cause of wildly varying durations for a single query: user-defined functions. Scalar…
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1 query, 3 parameters, 3 different plans

Parameter Sniffing in SQL Server 2019: Adaptive Joins

So far, I’ve talked about how adaptive memory grants both help and worsen parameter sniffing, and how the new air_quote_actual plans don’t accurately show what happened. But so far, I’ve been using a simple one-table query – let’s see what happens when I add a join and a supporting index: Transact-SQL CREATE INDEX IX_OwnerUserId_Includes ON…
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New columns in existing objects

New Objects, Columns, and Messages in SQL Server 2019 CTP 2.3

SQL Server 2019
6 Comments
Sure, there’s official documentation on what’s new in SQL Server 2019, but Microsoft’s notorious for slipping undocumented stuff in. Sometimes these new features become officially documented in subsequent preview builds, like CTP 2.2’s initial plumbing for Accelerated Database Recovery that went officially public in CTP 2.3, and other times they never see the light of…
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SQL Server 2019 Result Set Caching?

SQL Server 2019
5 Comments
Friday’s new CTP 2.3 added a few new fields to sys.databases: But the highlighted one has me all tingly inside, kinda like the first time I heard Winona Ryders use the word “chainsaw” in a sentence. (Bonus points for readers who get that reference.) I don’t have any answers yet, folks. I just have questions.
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