virtual joins

[Dave Airey]

I noticed JMP 13 and Spotfire 7.5 have virtual joins or similar for multiple data tables. So you don't have to physically join or merge data tables to pull data together with a unique identifier. Does Stata have this capability? Should it? It is supposed to save memory and make data changes faster in large data sets in some situations.

[William Lisowski]

So you don't have to physically join or merge data tables to pull data together with a unique identifier.

I'd replace "physically" with "explicitly". There is no magic going on, it's just that views or virtual joins or whatever hide the details from you. When you're running the same code repeatedly on data tables that are changing, it can add elegance. When you're running the same code on unchanging data tables, it can be more efficient to create a file of explicitly merged data and reuse it repeatedly.