Intermediary between the complete enumeration of all samples and the drawing of a few samples at random lies the Balanced Bootstrap, (see Gleason, 1988, American Statistician,263-266) for a simple algorithm.
The idea is that as when we count all
samples
each observation has the same chance of appearing,
we would like to have each observation appearing
overall the same number of times
after all
bootstrap resamples have been drawn.
We can be ensured of this by taking a list of
repetitions of each of the observations
and repeating them
times,
take a permutation of these
values and then take the first
as
the first sample, and so on.