Whether to use UNION or OR in SQL Server Queries

Recently I came across with an article on DB2 about using Union instead of OR. So I thought of carrying out a research on SQL Server on what scenarios UNION is optimal in and which scenarios OR would be best. I will analyze this with a few scenarios using samples taken from the AdventureWorks database

Top 10 Index T-SQL Statements That SQL Server DBAs Should Know

Indexes speed retrieval of rows from database tables or views. Here are the top index-related T-SQL statements that SQL Server DBAs should know.

Optimizing a cursor based routine – Part 2

In the second part of his optimization series, Dave Ballantyne shows us how to add conditional logic to set based, more efficient T-SQL code.

Optimizing a cursor based routine – Part 1

Learn how you can remove a cursor and optimize a routine that loops through a series of data and performs various calculations in this short article from Dave Ballantyne.

SELECT and WHERE without FROM

Date Time range

AVG function

Using a Variable for an IN Predicate

How to use a passed string variable for an IN type predicate in your queries as a way to more efficiently handle an array of strings.

The 5 First SQL Errors to Check For

Is your SQL query crashing? Nine times out of ten it will be for one of these 5 reasons!

Returning 0's in a SUM (SQL Spackle)

Learn how you can sum data by hour and by day while showing 0 values in your result sets for those time periods without a sum in this short article by Patrick Cahill.