Containing Select Columns in Aggregate Functions to Improve Performance in MS SQL

Recently I have been working on some MS SQL statements when I noticed a trick that improves performance by almost double. And that most people don’t know.

When working with joins and aggregate functions in the same query, we frequently face this error when we don’t add the select columns to the group by clause, even though the query will return one row by logic

from DZone.com Feed https://ift.tt/2OqJpXr