In my previous blog, I discussed the approximate count of unique values for which a predefined function is available in Impala (NDV), Oracle 12c (APPROX_COUNT_DISTINCT) and in MongoDB (estimatedDocumentCount()).
However, I didn’t mention about SQL Server since there is no such function available in the versions I am using. However, the function has been introduced in SQL Server 2019.
The function Approx_Count_Distinct does the same thing as mentioned in my previous blog.
If you want to know more about this function, I would suggest you click here. This guy (Rajendra Gupta) didn’t leave any opportunity to discuss this functionality as he concentrated on each piece and clarified each and every point.