This FAQ is for Stata 11. It is not relevant for more recent versions.

How can I use a dataset that is larger than the available RAM?

Load the dataset using the virtual memory system. This step requires you to start Stata with the /k option set large enough to hold the dataset. Once the dataset is loaded into memory, use the compress command to see if the variables can be stored using less memory. If so, save this dataset and exit from Stata. If you can now load the dataset into memory using only the available memory on the computer, then the problem is solved.

If your dataset is compressed and still will not fit into the available RAM of your computer, then use only those variables from the dataset that are necessary to run the commands in your analysis. If this allows you to load in the dataset using only the available memory on the computer, then the problem is solved.