Edward Haynes

Over 20 years experience in SQL Server development & administration, and creator of "Query Shaping" an innovative SQL query optimisation technique.
Find me on LinkedIn:
https://www.linkedin.com/in/edward-haynes-sql/

SQLServerCentral Article

Query Performance Diagnostics with sp_PerfSQ

This article discusses sp_PerfSQ a diagnostic tool designed to quantify performance features of database queries with active requests. It includes a behavioural parser and can assist in troubleshooting complex performance issues.

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2021-12-24 (first published: )

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Technical Article

sp_PerfSQ

A diagnostic tool for identifying Performance features of active SQL Queries. It collects performance detail from DMVs for queries with executing requests and is designed to demonstrate and quantify Query Shaping optimisation techniques by: quantifying query workload and throughput characteristics providing behavioural descriptors of potential performance inhibitors - refer column ThrottlePotential The ThrottlePotential column is […]

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2019-11-07

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Question of the Day

Fun with JSON II

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 t1.[key] AS row,
       t2.*
FROM OPENJSON(
     (
         SELECT t.* FROM #test_data AS t FOR JSON PATH
     )
             ) t1
    CROSS APPLY OPENJSON(t1.value) t2;

See possible answers