But all a good discussion - I have never used a binary index and so had to look it up. Might come in handy some day if there is a true/false answer on a field expression.
Thanks!

>You read my mind via my not well formulated question perfectly!
>Binary Index should speed up that particular subquery, but if empty(partfile.Date_Closd ) is not used elsewhere in table filtering operations, your current approach probably is best, as overindexing produces its own pain points.
>
>regards
>thomas
>
>>It is non-nullable. Have a machine index, not binary. The index is used in other ad-hoc queries where the users can specify a closing date range. Binary would just be for indexing if empty or not correct (at least that is what I am guessing you are getting at).
>>
>>Albert
>>
>>>Hmmm, seems to big a win - did you have a BINARY INDEX on partfile.Date_Closd ?
>>>(guessing that this is non-nullable)
>>>
>>>>Made the changes and that indeed worked better and faster.