Re: Sequence error in MR

for the record, the only example I can think of that Matching records
processing has over any of the others techniques described to replace it,
is in this particular situation

you have two or more files and you need to read each and every record of
each file (or a specific subset, of each file) and do one thing if it has a
match in the other files, or do something else if there is not a match.

no sql technique or setll/read that I know of will process this scenario
more efficiently than matching records.

I had this situation once, and that was the last time I wrote an MR
program.

and that was more years ago than I care to remeber.  ;)

rick