any DD with an EQ constraint can be used to reproduce it.
for example
to any view add a constrain procedure as follows
for example lets say we want to constrain to only orders from a specific customer
Procedure OnConstrain
Constrain ORDHDR.CUSTOMER_NUMBER EQ 1000
End_Procedure
you would of course expect the SQL statement to be something like
select col1, col2, .. from ORDHDR where CUSTOMER_NUMBER = 1000
would make sense
now watch the SQL statements created by the driver and you will see the following
select col1, col2, .. from ORDHDR where CUSTOMER_NUMBER < 1000
hmmm. These are the records i def do not want to see.
this in combination with complex sql filters leads to sever slow downs. You can of course program all the constraints as sql filters but you cant really remove them from constraints either because then the constraint engine goes nuts again.