What is the real advantage to use libraries?

Question

Hello

I'm trying to understand the real advantage to use libraries (Ecoinvent library).

When I import Ecoinvent library in the database everything begins to be complicated.

I can not modify input/output data of a dataset unless I copy it.

If I try to calculate directly a dataset I must create a product system.....?????

If I try to read the direct impact I obtain errors so it's unuseful.

Someone can explain me how to use correctly libraries?

The openLCA manual explain only how to import library in a database but it does not give information how to use it.

Thanks and sorry if my question is silly.

Comments

I have the same question. Also when the database or Library is used when you have both installed?  I believe it is read-only and for some processes this is not really the best way to work.

Answer 1

Hi, so I try - 

first, at least in 2.6, I am not aware of mistakes when checking direct impacts with libraries

(an example with PSILCA developer database and openLCA 2.6)

a library has several advantages:

- it cannot be modified by accident (you have the original result, always)
- calculation is much faster and less resource-consuming for big databases (e.g. again PSILCA developer: creation of the product system takes 5 seconds, calculating the product system 5 seconds, RAM required maximum 2 GB, while without a library, you need several minutes and about 70 GB RAM on a really powerful computer). But the results are as granular as if you calculate the full database, so it is different from using system processes: 

- the model graph is less messy as the library is only one box and you can focus on your foreground system (if you only have the database and no foreground system, it looks like this: 

again PSILCA developer).

So, thank you for your question, it was not at all silly (it is good to ask when new things come up: why does this makes sense).

Best wishes,

Andreas