Postgres replication

Dear All

I have a application running at various locations with backend as postgres
Slony is configured at all locations for replication at local site anda central server where each site has its own database instance.

Now we wish to merge data collected from all the sites into one database instance to provide consolidated view

database schema is same at all the places
However as the application is still under development the schema maychange. however the change will happen at all the locations.

Pls suggest a solution

with regards


Nalini S. Nautiyal