I am designing a System that will include Several large databases for each market the company is in. Each market will have many thousands of customers. Each customer will have a database to encapsulate their data. The question is
1. Is it better to have fewer databases vs 1 database per customer?
2. Is there a performance issue with many thousands of databases being accessed on one SQL server?
3. Is there a performance issue with a Database referencing data from other databases?
Has anyone in this forum worked on a large scale project of this type and if so what was your design methodology to overcome these issues. The many db design conceptually makes a lot of sense but does it make sense from a DB point of view?