Does spark.sql("DELETE FROM ...") need terminal operation?

I have a simple Spark code

val sql = "DELETE FROM table_name"
spark.sql(sql)

My code reviewer said that doesn’t work without "terminal" operation like .show()

But I am pretty sure it is works

Terminal operation is needed in case of "SELECT ..." operations

But not in case of "execute" operations

Please help!

It would be great if any documents is exist