You can easily import your data into R by dumping your data as a CSV file (and SQL as well). R will easily perform the operations you want. You can then access an SQL program (SQLite is easy) from within R and use R as your frontend (interface). The other issue is that R is free and you can probably get this solution working without any outside support.
The point the replies make here is that SQL queries will easily perform the numerical operations you want, whilst R can perform advanced stats/maths, which SQL can't. In addition,
1. Why use a complicated frontend?
2. R has data volume limitations
3. 967
R is not well suited for multiple user access
Point 1 Advantages of R, I would simply mention that, besides a databases interface, if you ever wanted to do more complicated stuff - e.g. graph your data - then R is really good. ggplot2 is an industrial standard graphing package within R, its a bit complicated to use (but not really) and there at least 2 books dedicated to it. If want to perform data munging for example a time series analysis, which economists do all the time, R is really good.
Point 2 However, R has limitations on the amount of data it will handle at any one time, the heavy duty databases mentioned here will not.
Point 3 This is a very good point and one you need to consider carefully. It is really restricted for an individual user who knows how to use R, which is not ideal for accessing the database. For example the R specialist might be on sick-leave that day and how to you access your database?
I'm not from the commercial sector (you can probably tell), a compromise maybe to have a direct heavy duty SQL style database, which R can access once it is setup via a DBI (database interface).
Word of warning The days of Microsoft Access are over, when a database could easily be setup and queried. The databases spoken about here are not free (Access was effectively free with the old MS packages) and will require external support to set them up. Personally, I would do the R thing, because without timeseries and graphs what is modern economics? (We do the same thing in academic medical). 967