ISNULL vs COALESCE

Find identical duplicate indexes

The purpose of this query is to find identical duplicate non-clustered indexes i.e. indexes on same table with same columns in same order. If you have a need to...
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How to delete a lot of data from a SQL Server database

How to delete data efficiently When we delete data from a table in SQL Server, we can often find that the delete is slower than even the original insert,...
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Testing Maximum Rows in Table Value Constructors

Solomon Rutzky dives into how big a table value constructor can be in terms of rows: On 2019-05-08, a helpful individual, Michael B, commented on my answer saying that the...

Dropping Tables in Bulk

Let’s assume that you have lots of tables that need to be dropped according to some...

Tutorial on SQL (DDL, DML) on the example of MS SQL Server dialect

Introduction This tutorial includes information about SQL (DDL, DML) that I have gathered during my professional life. This is the minimum you need to know while working with databases....

Maximum Number of Rows for the Table Value Constructor

What is the maximum number of rows for the Table Value Constructor? And, do different uses of it behave differently?… Continue reading Maximum Number of Rows for the Table...
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Strange Sorting

T-SQL bugs, pitfalls and best practices – subqueries

Itzik Ben-Gan resumes his blog series on T-SQL bugs, pitfalls, and best practices, treating an issue with correlated column references in subqueries.
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Temporary Staging Tables

Watch this week’s episode on YouTube. SQL Server Spool operators are a mixed bag. On one hand, they can negatively impact performance when writing data to disk in tempdb....
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