Cardinality Estimation for a Predicate on a COUNT Expression
Paul White takes you on an optimizer journey, exploring how SQL Server comes up with cardinality estimates for COUNT queries.
2017-05-17
3,222 reads
Paul White takes you on an optimizer journey, exploring how SQL Server comes up with cardinality estimates for COUNT queries.
2017-05-17
3,222 reads
Aaron Bertrand shares some insight about early changes to Plan Explorer that help to provide you with the most accurate information we can.
2016-04-04
2,780 reads
The Query Optimiser needs a good estimate of the number of rows likely to be returned by each physical operator in order to select the best query plan from the most likely alternatives. Sometimes these estimates can go so wildly wrong as to result in a very slow query. Joe Sack shows how it can happen with SQL Queries on a data warehouse with a star schema.
2012-12-10
1,163 reads
By Brian Kelley
If you want to learn better, pause more in your learning to intentionally review.
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If you’ve used Azure SQL Managed Instance General Purpose, you know the drill: to...
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Ramblings of a retired data architect Let me start by saying that I have...
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Hi all, I recently moved to a new employer who have their HA setup...
I have this data in a SQL Server 2025 table:
CREATE TABLE Response ( ResponseID INT NOT NULL CONSTRAINT ResponsePK PRIMARY KEY , ResponseVal VARBINARY(5000) ) GOIf I want to get a value from this table that I can add to a URL in a browser, which of these code items produces a result I can use? See possible answers