Implementing multitenancy
Multitenancy is the ability by which an application can act (and seem) different when observed in different ways. Think, for example, of a website that displays a different look and feel when it is accessed as http://abc.com or http://xyz.net. Here, we are talking about the same physical site having two different domain names bound to it, abc.com and xyz.net, which are the tenants.
When it comes to relational databases, there are essentially three techniques for achieving multitenancy:
- Separate database: Each tenant's data is kept in a separate database instance, with a different connection string for each; the multitenant system should pick automatically the one appropriate for the current tenant as shown in the following figure:
Separate databases
- Separate schema: The same database instance is used for all the tenants' data, but each tenant will have a separate schema; not all RDBMSs support this properly, for example, SQL Server doesn't, but Oracle...
