inquire about preserve and restore

[Yao Zhao]

I need to drop tons of variables in my data set for panel A task. And I need to go back to the original data set to do for panel B task. My codes are:

preserve
* codes for panel A task
gen vara
restore
preserve
* codes for panel B task
gen varb
restore

Do you have better ideas? And I need to do a ttest with vara and varb.

[Joseph Coveney]

What version (release) of Stata do you have? If you have the newest (16.0, 16.1), then you might want to look into frames as an alternative.

help frames