st: Not enough memory message after -keep in 1-

[Sergiy Radyakin <serjradyakin@gmail.com>]

Dear All, Stata shows some rather inefficient behavior in the following code:

clear
set mem 1g
set obs 52428770
gen double x=uniform()
memory
keep in 1

(11MP/32bit and earlier 32-bit versions, not tested with Stata 12).

Seems that Stata is requiring memory for an additional variable (I
suspect "touse")
to keep the first observation, which in this case is causing a "not
enough memory"
error.

I was under impression that "in A/B" is present in the Stata's syntax
precisely for
efficiency reasons, but from above it follows that it is fully equivalent to
if inrange(_n, A,B).

Is this correct or how is "in" different?

Thank you, Sergiy
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