This is just going to be a brief post, because there have been other blogs about this topic – I just wanted to add a small piece on top of it ;-).
Our two Italian friends Stefano and Duilio already wrote some blogs about the upcoming performance improvements regarding the new feature in Business Central, that includes a new data model for table extensions. In Short: in stead of having a new table for every single table extension, the extension-tables will be consolidated into only one extension table – which avoids a massive amount of JOINs in the SQL statement, which obviously – you can already guess – will result in a performance boost.