Also, this is [an XY Problem][1]. Instead of telling us what the solution must be, tell us what your actual problem is and let the forum's brain trust suggest better solutions. Chances are excellent that you do not actually need 34 digits of precision. That's roughly sufficient for universe-scale problems at the precision of dust motes. That might sound good until you realize that no computer on the planet can usefully run a program big enough to do anything useful with that sort of model. In other words, Decimal128 is stupid-big for most purposes. There's probably a better solution for your problem, if only we knew what it was. [1]: http://xyproblem.info/