Am incercat varianta cu cursor, insa este de 4-5 ori mai lenta decat varianta cu select (asa cum era initial). Codul sursa pentru cursor este afisat mai jos:

--drop table A_tmplstFisaCont

select *, cast(0 as decimal(28,6)) as Sold into A_tmplstFisaCont from A_lstFisaCont order by cont, datainr, nds

update A_tmplstFisaCont set sold = 0

DECLARE @cont varchar(16), @datainr datetime, @nds int, @coduser int, @debit decimal(28,6), @credit decimal(28,6), @sold decimal(28,6)

DECLARE abc CURSOR FOR
SELECT cont, datainr, nds, coduser, debit, credit, sold
FROM A_tmplstFisaCont
--ORDER BY cont, datainr, nds  --daca pun order by, cursorul este read-only si nu pot face update pe el

OPEN abc

FETCH NEXT FROM abc
INTO @cont, @datainr, @nds, @coduser, @debit, @credit, @sold

WHILE @@FETCH_STATUS = 0
BEGIN
  UPDATE A_tmplstFisaCont SET Sold = isnull((select top 1 sold from A_tmplstFisaCont where cont = @cont and coduser = 1),0) + debit - credit
  WHERE CURRENT OF abc
  
  FETCH NEXT FROM abc
  INTO @cont, @datainr, @nds, @coduser, @debit, @credit, @sold
END

CLOSE abc
DEALLOCATE abc
GO

(Sunt ceva greseli in cod in sensul ca nu-mi calculkeaza soldul, inca nu mi-am dat seama unde, dar nici nu am cautat din moment ce ma intereseaza in primul rand sa fac algoritmul sa ruleze mai rapid.)

Am incercat si varianta cu FAST_FORWARD, dar tot fara rezultat. Codul este si el foarte lent in comparatie cu SELECT in SELECT:

drop table A_tmplstFisaCont

select *, cast(0 as decimal(28,6)) as Sold into A_tmplstFisaCont from A_lstFisaCont order by cont, datainr, nds

alter table A_tmplstFisaCont add [iId] [int] IDENTITY (1, 1) NOT NULL

go

CREATE CLUSTERED
INDEX [iIdIdx] ON [dbo].[A_tmplstFisaCont] ([iId])
ON [PRIMARY]

GO

update A_tmplstFisaCont set sold = 0

DECLARE @id int, @cont varchar(16), @datainr datetime, @nds int, @coduser int, @debit decimal(28,6), @credit decimal(28,6), @sold decimal(28,6)

DECLARE abc CURSOR FAST_FORWARD READ_ONLY
FOR
SELECT iid, cont, datainr, nds, coduser, debit, credit, sold
FROM A_tmplstFisaCont
ORDER BY iid

OPEN abc

FETCH NEXT FROM abc
INTO @id, @cont, @datainr, @nds, @coduser, @debit, @credit, @sold

WHILE @@FETCH_STATUS = 0
BEGIN
  UPDATE A_tmplstFisaCont SET Sold = isnull((select top 1 sold from A_tmplstFisaCont where cont = @cont and coduser = 1),0) + debit - credit
  where iid=@id
--  WHERE CURRENT OF abc
  
  FETCH NEXT FROM abc
  INTO @id, @cont, @datainr, @nds, @coduser, @debit, @credit, @sold
END

CLOSE abc
DEALLOCATE abc
GO

PS: Am inlocuit money cu decimal(28,6) pentru ca asa apare in BD mea.

Alte idei ar mai fi?