A library is an immutable database tha can be even pre-calculated (but don't has to) to speed up calculation. For example, input-output databases like PSILCA or exiobase get massive reductions in the calculation durations, whereas for ecoinvent, the non-library database or the non-precalculated libraries in openLCA are already so fast in calculation speed that the speed advantage from pre-calculated libraries is not needed here.
But even if not pre-calculated, a library is an immutable database, meaning that it cannot be changed anymore. Because of this immutable nature, there is no possibility that modifiable parameters exist inside the library itself. Of course, parameters can still be used in the foreground processes that do not belong to the library, parameters can also be used in the foreground to vary inputs from the "background" library, but inside the library itself everything is fixed.
So when the library is created with openLCA, the set values of the parameters are "frozen" in and the parameter results are written into the exchange amount values. So the parameters do not exist anymore, but they are applied as set in the moment when the library is created. You will also see that, for example, different cost values inside a process are calculated for that process and put into the quantitative reference, or that units are changed to the reference unit of the specific unit group (and adapting the exchange amounts accordingly). So the library is kind of writing everything "in stone", but keeping the calculation results unchanged to the non-library database.
Do you have a use case when to use a library together with parameters inside that library? Why not using the non-library database for such cases?
