How to use group by and distinct operator in SQL Server?

Can we use GROUP BY and distinct together?

Well, GROUP BY and DISTINCT have their own use. GROUP BY cannot replace DISTINCT in some situations and DISTINCT cannot take place of GROUP BY. It is as per your choice and situation how you are optimizing both of them and choosing where to use GROUP BY and DISTINCT.

Do you need GROUP BY for distinct?

The group gives the same result as distinct when no aggregate function is present. GROUP BY is required if you're aggregating data, but in many cases, DISTINCT is simpler to write and read if you aren't aggregating data.

Is GROUP BY and distinct the same?

Distinct is used to find unique/distinct records where as a group by is used to group a selected set of rows into summary rows by one or more columns or an expression. The functional difference is thus obvious. The group by can also be used to find distinct values as shown in below query.

Why GROUP BY is faster than distinct?

DISTINCT would usually be faster than GROUP BY if a) there's no index on that column and b) you are not ordering as well since GROUP BY does both filtering and ordering.