Doug,

Am going to pull the query out and see what I can do about indexes. Prestatie table contains about 700.000 records and joins to PrestatieHistoriek which contains about 900.000 records and growing at about 100.000 a month (2 months in production now).

What worries me a bit is that the procedure executes reasonably fast executed from QA but when in trigger or launched from code it hangs with blocking occurring.

Am also looking to make a little working example to test with and will post the code when I am finished. Don't know if it will be today because it's almost 6PM over here and that means the weekend begins...