Multisite with single database : can you show me the light?

Hi,

I'm using : Elgg 1.8.8

I was wondering if it is actually possible to make this configuration :

test1.example.com with one installation

test2.example.com with another install

But the whole thing with only one database, which means the content created in one subdomain can be displayed in another subdomain

I can see I have to do some hacks near 'sites_entity' and 'datalists' tables but I'm actually struggling

I hope someone can help me

N.B : The Multi-site plugin by Marcus can't actually do this I think because it uses one database per install?