Difference between Union and Union All in SQL?

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Manikandan Murugesan

1.2k

Union -> It combines only unique rows. Performance is slower due to this. Union All -> It combines all rows. Performance will be better as it combines all rows.

Tharunkumar Magudeeswaran

Union - returns all the values from 2 queries excluding dups
Union All - returna all the values from 2 queries including dups

Umang Pawar