I recently dropped many unneeded fields. I thought that this would help performance, but it has increased the calculation time on many of my objects by a factor of ten. Can any one explain to me why this is happening? shouldn't it take less calculation time as there are less fields to deal with?
Within the UI not used fields shouldn't be impact the calculation-times from the objects but skipping/dropping them will reduce the loading times and the filesize / RAM footprint and therefore the times for opening and saving the app.
Are the calculation-times now significantly longer as before its quite likely that you dropped any used field and now some table-association and/or some loads (joins, exists-filter, combined keys and similar stuff) don't work properly anymore. I assume that a check of the associations and number of records in the tableviewer from the old app vs. the new one will show the mistake quickly.