Here is my scenario
Master1 hosting DB1
Master2 hosting DB2
...
MasterN hosting DBN
replicate to:
Slave1 hosting DB1,DB2... DBN
I've read similar questions and they recommend to start different instances at Slave1 and simply do MasterN-Slave1(instanceN) replication, as instructed here:
https://stackoverflow.com/questions/7544241/single-slave-multiple-master-mysql-replication
That would be piece of cake, but running different instances might be a waste of resources.
I really want to achieve this with an single DBMS instance at Slave1, and if possible with PostgreSQL; but can try with MySQL if there is a solution for this.
Any help is appreciated.