there are many situations in which SQL Server (or Oracle) is simply not a practical solution - but large volumes of data still need to be handled

Give me an example please...

Read the following articles showing some of the advantages of SQL Server compared to VFP (if you have read them - read them again):

http://www.microsoft.com/technet/prodtechnol/sql/maintain/featusability/extscale.asp
http://www.microsoft.com/technet/prodtechnol/sql/maintain/featusability/dss.asp
http://www.microsoft.com/technet/prodtechnol/sql/maintain/featusability/replica.asp
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwindev/html/msdn_bldcli~1.asp
http://www.microsoft.com/sql/evaluation/overview/dataware.asp
http://www.microsoft.com/sql/techinfo/BI/terabytecube.asp

I DO NOT ever think that SQL Server is best in all cases.


With its local cursor engine, tight coupling between language and data, and powerful features such as object-oriented programming, Microsoft Visual FoxPro 7.0 is a great tool for building database solutions of all sizes, from desktop and client/server database applications to data-intensive COM components and XML Web services.
Visual FoxPro is a powerful rapid application development (RAD) tool for creating relational database applications.


But...

Microsoft's SQL Server allows the use of a large and complex database, and will handle large volumes of traffic. Microsoft recommends the use of SQL server for high traffic sites with processor intensive queries.


So depends on the solution... but for most cases when wee need to handle really large amounts of data, SQL Server has no high-performance and easy-maintance alternative.

Kind Regards