Hello Andreas, Tuesday, April 21, 2020, 6:17:00 PM, you wrote:
> On 4/21/20 5:06 PM, Eugen Konkov wrote: >> Hi. I read the thread. >> >> Probably this fiddle will be helpful for testing: >> >> https://dbfiddle.uk/?rdbms=postgres_12&fiddle=abe845142a5099d921d3729043fb8491 >> >> I recently encountered a problem: >> Why Window-specific functions do not allow DISTINCT to be used within the >> function argument list? >> >> sum( DISTINCT order_cost ) OVER ( PARTITION BY invoice_id ORDER BY >> invoice_id, group_id RANGE unbound preceeding and unbound following ) >> >> behavior is quite deterministic: >> >> ORDER BY will create peers in partition >> DISTINCT will get only one peer >> >> I resolve my problem via two subqueries, but it seems this logic may >> be applied to window functions (did not check this for other functions >> thought) > Sorry, I do not follow. What problem did you encounter? Lack of DISTINCT for window function SUM -- Best regards, Eugen Konkov
