Mounting NB on- the-fly

I must admit I am not sure what it means to Attach or Mount a lakehouse to a Notebook. Is Attach and Mount the same thing? 

Anyway, I am unsure if the mssparkutils mount method is able to make a lakehouse the default lakehouse for the Notebook.

Okay, it can mount one or more lakehouses to the Notebook, which per my current understanding makes it possible to use relative directory paths (e.g. useful for os module and Pandas).

However, if you want to use Spark SQL, I guess we would need to be able to mount a lakehouse as the default Lakehouse of the Notebook? I am not sure if the mssparkutils mount method can do that.

It seems I am able to mount a Lakehouse as the default Lakehouse by using the solution to this forum thread: Solved: Re: How to set default Lakehouse in the notebook p... - Microsoft Fabric Community

However I need to use this code (need to add the -f argument):

%%configure -f
{
    "defaultLakehouse": {  
        "name": "<lakehouseName>",
        "id": "<lakehouseID>",
        "workspaceId": "<workspaceID>"
    }
}

It means the Livy session will need to restart. I don't know what the Livy session is, however it seems all variables will get lost by doing that. 

I also didn't find out how to insert the lakehouseName, lakehouseID and workspaceID as variables.
So I had to hardcode those values in the JSON structure in the %%configure cell.
I guess it should be possible to pass variables into the JSON structure, however at the moment I don't know how to do that.

Other than that, it seemed to work, when I hardcoded the values.