In my last blog I explained what a columnstore index is, in this blog, we will dive into creating a clustered columnstore index and look at the performance differences...
2019-07-31 (first published: 2019-07-10)
552 reads
Recently I reviewed filtered indexes, this time let’s look at columnstore indexes. These indexes are very useful for data warehouse workloads and large tables. They can improve query performance...
2019-07-11 (first published: 2019-06-26)
1,274 reads
When you run a query twice, and get dramatically different run times, your first step can be to try to identify the differences in execution plans. For many that...
2019-07-05 (first published: 2019-06-19)
930 reads
In this post, we continue with another beginner’s blog of database features that may be unknown to many. Let’s take a look at filtered indexes. Many database administrators are...
2019-06-10 (first published: 2019-05-22)
767 reads
I give performance presentations at many different events to all levels of SQL Server professionals. Over time I’ve noticed that some DBAs and developers have never looked at the...
2019-05-29 (first published: 2019-05-15)
2,097 reads
I am very excited to announce I will be delivering a pre-conference session on SQL Server Performance Tuning on November 5th at PASS Summit 2019. If you have ever...
2019-04-24
87 reads
Another quick post of simple changes you can make to your code to create more optimal execution plans. This one is on implicit conversions. An implicit conversion is when...
2019-04-29 (first published: 2019-04-17)
1,147 reads
One of the easiest things to fix when performance tuning queries are Key Lookups or RID Lookups. The key lookup operator occurs when the query optimizer performs an index...
2019-04-17 (first published: 2019-04-03)
725 reads
March is Women’s History Month, to celebrate the PASS Women in Technology Virtual Group (@PASS_WIT) held a webcast featuring prominent...
2019-04-09 (first published: 2019-03-20)
1,036 reads
I’ve seen many people go through the trouble of setting up database mail and configuring SQL Agent Alerts only to...
2019-03-13
266 reads
By Vinay Thakur
Continuing from Day 3 where we covered LLM models open/closed and their parameters, Today...
By Steve Jones
One of the nice things about Flyway Desktop is that it helps you manage...
By HeyMo0sh
Microsoft Fabric (not to be confused with the more general term “fabric” in DevOps)...
I'm fairly certain I know the answer to this from digging into it yesterday,...
Hi Team, I am trying to refresh the Azure Synapse Dedicated pool from production...
hi everyone I am not sure how to write the query that will produce...
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