SQL Server vs Oracle Query Statistics to Improve Performance
In this article, learn how to query cached query statistics and execution plans for Oracle or SQL Server to identify code that can be optimized to improve performance.
2023-07-21
In this article, learn how to query cached query statistics and execution plans for Oracle or SQL Server to identify code that can be optimized to improve performance.
2023-07-21
The SELECT statement is used to retrieve information from a database. Following the execution of a SELECT statement, a tabular result is held in a result table (called a result set). It allows you to select the table columns depending on a set of criteria. In this article, I will introduce the basic SELECT statement fetching data from just one table.
2023-06-21
This article looks at the way in which you can convert unmanaged devices to the ASM filter drive in an Oracle system.
2022-03-04
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To troubleshoot poorly performing SQL in Oracle, you must understand which transformations the optimizer has made. Jonathan Lewis demonstrates several possible optimizations for one query.
2022-02-09
In this article we look at how to install SQL Server and Oracle using PowerShell to create development environments using Windows Containers.
2022-01-28
In this article we look at how to use string functions to concatenate, replace, trim and get substrings in SQL Server, Oracle and PostgreSQL.
2021-10-25
Oracle has built-in functionality to analyze text. Sanil Mhatre demonstrates how to perform a sentiment analysis on data stored in a table using Oracle Text.
2021-09-15
Oracle added several enhancements to the sequence object in version 12c, including an “identity” column feature. Jonathan Lewis explains how to work with these new features.
2021-09-10
In this article we look at the similarities and differences for views in SQL Server, Oracle and PostgreSQL. We also look at indexed views, materialized views and updatable views.
2021-08-16
Oracle sequences supply unique numbers that can be used when populating tables. In this article, Jonathan Lewis explains the typical uses of Oracle sequences.
2021-08-04
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Comments posted to this topic are about the item Fun with JSON II
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Comments posted to this topic are about the item Answering Questions On Dropped Columns
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