Question: How is the function COUNT_BIG() used and what is the difference with COUNT()?
Answer: Both COUNT(*) and COUNT_BIG(*) return total number of rows in a table where the value of the column is NOT NULL.
The difference is COUNT(*) returns INT datatype and COUNT_BIG(* ) uses the bigint datatype
When to use COUNT_BIG? If you think the result count is greater than the maximum value of integer