FogBugz was designed from the ground up to be scalable to massive databases. The database itself can be stored in Microsoft SQL Server; Microsoft has reported production databases as large as 5 terabytes (5319 GB) in SQL Server. Our database schema is highly optimized with carefully selected indices, and since it’s running on industry-standard database servers you can performance tune as necessary to optimize for your particular needs.
Our own production FogBugz database has over 800,000 cases in 5GB and runs quickly on an inexpensive Dell server without generating any significant load. If need be, you can create a farm of FogBugz servers accessing a single clustered SQL Server database. We have fine-tuned the code to prevent accidental data overloads; for example if you try to do a query that is going to take two hours and return 100,000 rows, we’ll stop after the first 500.