Salesforce Core Platform Data Layer 

Thanks!

It actually does. You can read more details in our Platform Multitenant Architecture document here: architect.salesforce.com/fundamentals/platform-multitenant-architecture

@@SalesforceArchitects thanks for the reply . Yes have read it already, but it says, it has nearly 500 physical columns. since sql server takes the entire row from disk for processing , won’t it make the fetch slower and high ram consuming for queries made with few select columns ? I assumed it has few data tables of 50-100 columns and joined during data fetch. Please share your thoughts on this.

@@karthik8972 the back end database is actually not SQL Server... and the system doesn't retrieve the entire row directly from the database every time you run a query. Instead, it creates a set of virtual objects for each org at runtime and any queries that get run by that org execute against them.

@@SalesforceArchitects do you mean to say that salesforce doesn’t uses oracle as it storage server ? and it uses its own built db server ?