This is purely from performance standpoint and only for SQL Server. I am using SQL Server 2012. I am migrating from a different database server (Ctree). The databases are from less than 100mbs to about 2-3GBs, five in total. There are a lot of tables – over 400 tables in all.
Would it be better in terms of performance only to use a single database and multiple schema or multiple databases as is? The existing logic is that there are multiple databases and there are 7 different applications (C# – ADO.NET) that use these.
I highly doubt you’ll see any significant performance benefit from splitting this up into multiple databases, if those are all running on the same physical server machine in the end.
However: if you do split it up into several separate databases, you won’t be able to establish referential integrity using foreign key constraints across database boundaries – so that might be a drawback and a negative point.