SQL SERVER – Union vs. Union All – Which is better for performance? | Journey to SQL Authority with Pinal Dave

This article is completely re-written with better example SQL SERVER - Difference Between Union vs. Union All - Optimal Performance Comparison. I suggest all of my readers to go here for update article. UNION The UNION command is used to select related information from two tables, much like the JOIN command. However, when using the… Continue Reading...

Source: SQL SERVER – Union vs. Union All – Which is better for performance? | Journey to SQL Authority with Pinal Dave