I have a VBa App that creates this SQL:

UPDATE type INNER JOIN (select * from Mat_data in 'C:\sb-Data\sb\In Tray\New_18_1_2005.mdb') T1 ON type.SBKEY = T1.type_SBKEY SET Type.Name = [T1].[Type_name], Type.[Measure ID] = DLookup('[Measure ID]', '[Measure]', "'[Measure].[SBKey] = " & [T1].[Measure_SBKey] & "'"), Type.Wm_Ratio = dlookup("[id]", "[converter]","'[converter].[sbkey] = " & [t1].converter_sbkey & "'");

This SQL takes almost five and a half minuets to run with a smallish data sample. That is far to slow.

That's the challenge then a better way of asking for the same thing.