Add min/max to aggregate/aggregate2 about crush-tools HOT 2 OPEN

The interface needs to allow for textual and numeric min/max functionality.  
Options
for indexes/labels could be

-m/-M - numeric max 
-x/-X - lexicographic max
-n/-N - numeric min
-i/-I - lexicographic min

But I'm not especially fond of that last one.

Alternatively, perhaps we could track both kinds of min/max, and decide what 
kind of
values it was looking at after the fact.  If only numeric values appeared in a 
field,
use the numeric min/max; but if the field contained non-numeric characters in 
one or
more rows, use the lex min/max.  This could be complicated by the presence of 
commas,
currency symbols, etc., in otherwise numeric fields.

Another question: what is the correct way to handle empty fields?  Should they 
count
as a normal field value, or be ignored?

I think numeric is higher priority. And I like your alternate proposal. 

How hard would it be to add long command line args for this? Or use only long 
command
line args for lexicographical requests - as I imagine they would be much less 
frequent? 

nulls should probably be 0s in the case of numeric for convenience. Otherwise 
the
docs should clearly state something about using translate_field/sed. I can't 
think of
a case where nulls would be a useful lexicographical min - and in most reports 
I see,
nulls would be stripped with grepfield or they'd be an edge/error case. That 
isn't to
say the use case doesn't exist...