>>>
>>>The result of SYS(3054)is:
>>>

&mSqlCommand
>>>Rushmore optimization level for intermediate result: none
>>>Rushmore optimization level for table ivinvt: none
>>>Joining table ivinvt and intermediate result using temp index

>>>
>>>Good suggestion but I don't know why it is not using Rushmore.
>>>
>>>Thanks for the help.
>>
>Did you have ORDER by K_Ivinvt of Ivinvt table?
>- YES
>
>Did ivinvt.k_ivinvt AND c_chng.k_ivinvt have the same length (if they are strings)?
>- Same Size
>
>What is SET DELETED status (WAIT WINDOW SET{DELETED]))?
>- SET DELETED is ON

What type is K_Ivinvt?
If K_Ivinvt is some kind of numeric try:

SYS(3054,12,[TestMe])
UPDATE.....
WHERE K_Ivinvt = 1
MessageBox(TestMe)

and tell me the result.