> I recently switched a query component from TIBOQuery to TIB_Query. Since
> making the switch, there has been a huge performance problem. I have
> tracked it down to the fact that the OnCalculateField event is firing
> WAAAAAY too often. It seems like just about anything will cause this, but
> here's an example:
>
> If open the dataset, and then scroll to the last record (using the "last
> record" button on the TIB_NavigationBar, my CalculateField handler gets
> called for EVERY SINGLE RECORD in the database, rather than just the last
> one. There is no need to calculate the fields for records that it's just
> skipping past. I found this out by putting a break point in my
> CalculateField handler, and it breaks there for every single record in the
> database. When it hits the breakpoint, this is what the call stack looks
> like:
>
>
> TMainForm::OrderTableCalculateField
> TIB_Statement::DoCalculateField
> TIB_Row::CalculateFields
> TIB_Row::RefreshBuffers
> TIB_Dataset::SysFetchNext
> TIB_Dataset::SysFetchAll
> TIB_BDataset::SysLast
> TIB_Dataset::Last
> TIB_NavigationBar::BtnClick
> ...
>
> I don't really know anything about IBO internals, but I'm guessing that it
> has something to do with that SysFetchAll call.
>
> So...
>
> Why does it fetch all of the records when I jump to the last record? How
> can I prevent this?

It seems the performance problem is related to fetching all the records.
Were there some settings you did not move over from the TIBOQuery?

You can setup horizontal dataset refinement by making use of the
OrderingItemLinks property. Search these archives for instructions of how to
do it.

Jason LeRoy Wharton