I think the script in the article is a bit of a non-starter.

It is calculating the square root multiple times for each row.

You only need to test up to the square root of a number to test for primality, which is quite a saving:

declare @n  ...

For exhaustive methods it's quicker to only look at odd numbers.  There was a Youtube video a little while ago where they compared all different programming languages to determine...

I wrote this SQL Server table valued function a few years ago. It returns all the prime numbers less than 1 million in about 1 second.

Thank you, Jonathan. Almost every step in the execution plan now marked as "No Join Predicate" and the whole function now costs 100% with my original tally one...

You don't need to...

;WITH CTE AS 
(
    SELECT oven, 
           T.Hours,
      ...

Got no idea if this will work as you haven't posted any consumable data:

;WITH CTE AS 
(
    SELECT System, 
    ...

Python needs indentation to work.

Thanks for the reply.  This query took over 3 minutes to run and it still didn't produce a result so I cancelled it.  The run time on this one...

This is an equivalent query

SELECT T4.UNDERLYING_SYMBOL,
       T4.QUOTE_DATE,
       T4.EXPIRATION,
       T4.ROOT_SYMBOL
...

• This reply was modified 2 years, 3 months ago by Jonathan AC Roberts. Reason: wrong alias

Your SQL looks a bit odd. There is no point in ordering by something you are partitioning by. You have Car, Direction in the partition and also in the order...

SELECT y.ArriveDate, y.Car, x.arrival, x.direction, x.totalIn, x.totalOut, x.StationId, x.StationName
  FROM [Ridership].[dbo].[Rail2019] x
 INNER JOIN (SELECT DISTINCT ArriveDate, Car
        ...

SELECT rp.* 
FROM returned_products rp
WHERE rp.returned_products_reason NOT LIKE '%reason_[2-3]%'
;