Indexes directly affect the performance of database applications. This article uses analogies to describe how indexes work. The estimated execution plan feature of the Query Window is utilized to compare the performance of two queries in a batch.
2007-12-04
5,686 reads
2007-12-21 (first published: 2007-10-25)
1,421 reads
This is an enhanced version of my previous script: Prioritize Missing Index Recommendations (2005).To aid in evaluation of whether the recommended index is reasonable, I have added :1. counts for key columns and the total columns of the recommended index 2. the length/bytes for both key and all columns Note this is 'per row', not […]
2007-08-17
1,856 reads
To report indexes proposed by the database engine that have highest probable user impact. Note that no consideration is given to 'reasonableness' of indexes-- bytes, overall size, total number of indexes on a table, etc. Intended to provide targeted starting point for holistic evaluation of indexes.
2007-08-17
990 reads
This script will find foreign keys (on referencing table) that are not indexed in SQL Server 2005.
2011-12-20 (first published: 2007-08-10)
3,762 reads
Check Indexes on all databases and rebuild/reindex based on fragmentation
2008-02-01 (first published: 2007-04-05)
1,458 reads
2007-04-30 (first published: 2007-04-03)
1,688 reads
Since it is not possible to script only the primary keys of all tables with the SQL Server 2005 Management Studio, here a small script to get the create scripts for all existing primary keys of the current database.
2007-03-28 (first published: 2007-03-09)
4,302 reads
When AUTOSTATS is used in a database, we can sometimes use these automatically generated statistics to find columns where SQL Server has built statistics on non-indexed columns that may benefit from an index. This script finds these columns and displays the selectivity of them. This script can be useful in troubleshooting poorly performing databases by […]
2007-04-09 (first published: 2007-02-20)
1,756 reads
Most DBAs are constantly looking for ways to tune their servers to run better. Joe Doherty brings us the second part of his series on indexes with an in depth look at how the indexes are stored in your database.
2007-12-13 (first published: 2006-12-20)
14,365 reads
By HeyMo0sh
Microsoft Fabric (not to be confused with the more general term “fabric” in DevOps)...
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,...
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