Manually updating Statistics
Having up to date statistics is vital for getting the best performance out of your queries. Even though SQL Server automatically updates statistics in the background for you, you...
2021-02-16
228 reads
Having up to date statistics is vital for getting the best performance out of your queries. Even though SQL Server automatically updates statistics in the background for you, you...
2021-02-16
228 reads
I’ve mentioned previously how not having up to date statistics can cause problems in query performance. This post looks at something called the Ascending Key Problem which can badly...
2021-02-09
184 reads
When you don't have statistics, what does SQL use to calculate the estimated number of rows?
2021-02-04 (first published: 2021-01-26)
296 reads
Statistics objects are important for allowing the SQL Server Optimizer to make good estimates and form efficient execution plans. Related to that it's useful for us to understand when...
2021-01-25 (first published: 2021-01-18)
502 reads
Query Store is a configuration that is enabled per database, and the plans and stats for queries executed in that database are stored in the database itself. So what...
2021-01-18 (first published: 2021-01-11)
472 reads
Script to identify the most expensive queries on your database server using the Query Store DMVs. This allows you to look at data from a specific time frame, as...
2021-01-11 (first published: 2021-01-04)
695 reads
Here's a SQL Puzzle for the festive period. 2020 has been a year of many things but amongst it all, it has been the year of chess. The combined...
2020-12-24 (first published: 2020-12-15)
537 reads
Introduced with SQL 2016, Query Store was, probably without doubt, the most anticipated and talked out new feature. In this post we'll just take a brief look at it,...
2020-12-21 (first published: 2020-12-14)
934 reads
Recently Microsoft quietly let us know that TDE (Transparent Data Encryption) will be available in the Standard Edition of SQL Server 2019. If you don’t follow SQL topics on...
2019-11-12 (first published: 2019-11-05)
7,126 reads
If you’ve read about the Accelerated Database Recovery feature in SQL Server 2019 you could be forgiven for thinking it’s just about speeding up database recovery time in case...
2019-10-09 (first published: 2019-09-25)
952 reads
By James Serra
I’m honored to be hosting T-SQL Tuesday — edition #192. For those who may...
By Vinay Thakur
Continuing from Day 2 , we learned introduction on Generative AI and Agentic AI,...
Quite the title, so let me set the stage first. You have an Azure...
hi everyone I am not sure how to write the query that will produce...
Comments posted to this topic are about the item Rollback vs. Roll Forward
Comments posted to this topic are about the item Foreign Keys - Foes or...
I have some data in a table:
CREATE TABLE #test_data
(
id INT PRIMARY KEY,
name VARCHAR(100),
birth_date DATE
);
-- Step 2: Insert rows
INSERT INTO #test_data
VALUES
(1, 'Olivia', '2025-01-05'),
(2, 'Emma', '2025-03-02'),
(3, 'Liam', '2025-11-15'),
(4, 'Noah', '2025-12-22');
If I run this query, how many rows are returned?
SELECT *
FROM OPENJSON(
(
SELECT t.* FROM #test_data AS t FOR JSON PATH
)
) t; See possible answers