[CWB] Efficient way to count frequencies on large data

[Sébastien Jacquot]

Hi,
I'm looking for an efficient way to get the frequencies of repeated 
token sequences on large corpora.
At this moment I use:
R = ([][][][]);
count R by word cut 20;

Is there a faster way to do that in terms of performances? (I mean for 
example by directly grouping and counting the results rather than 
getting all the results and then count them?)
Thanks in advance.
Sebastian