help memory
可以查到您要的

指令参见其说明
Set maximum number of variables in Stata/MP and Stata/SE
        set maxvar # [, permanently]
where # is specified in bytes, kilobytes, megabytes, or gigabytes (b, k, m, and g may be typed in
uppercase), with the default being k, and where 2048 < # < 32767 in set maxvar.