Search on two core and two schema

[Damien Fontaine]

Hi,

I would like make a search on two core with differents schemas.
Sample :

Schema Core1
 - ID
 - Label
 - IDTaxon
...

Schema Core2
 - IDTaxon
 - Label
 - Hierarchy
...

Schemas are very differents, i can't group them. Have you an idea to 
realize this search ?

Thanks,

Damien