Schleifen Optimierung?

[Tyrolean]

Zitat von Blup:

z.B. so:

SQL-Code:

SELECT c.*, 
  (SELECT count(p.Customer_Number)
   FROM   Position p
   Where  p.Customer_Number = c.Customer_Number) Anzahl
FROM Customer c

Eigentlich am schnellsten müsste sein

SQL-Code:

SELECT c.*, 
  (SELECT count(p.Customer_Number)
   FROM   Position p
   Where  p.Customer_Number = c.Customer_Number and p.announcement_date > Date()) Anzahl
FROM Customer c