I thought there were issues associated with doing mutations inside iterators?
On Tue, Apr 10, 2012 at 10:35 PM, William Slacum <[email protected]> wrote: > I don't think you'd necessarily need a an aggregator for that, although it > doesn't seem like that's what you're doing here in the first place. Wouldn't > it be easier to set a summation iterator that also keeps a count of of > observations to do some server side math and then combine it all on the > client? That way you can have a time series and to get weekly averages you > just change your scan range. > On Apr 10, 2012, at 10:16 PM, David Medinets wrote: > >> I'm still thinking about how to use accumulo to calculate weekly >> moving averages. I thought that using the maxVersions settings might >> work to maintain the last 7 values. Then a program could simply sum >> the values of a given row. So this is what I did: >> >> bin/accumulo shell -u root -p password >>> createtable rolling >> rolling> config -t rolling -s table.iterator.scan.vers.opt.maxVersions=7 >> rolling> insert row cf cq 1 >> rolling> insert row cf cq 2 >> rolling> insert row cf cq 3 >> rolling> insert row cf cq 4 >> rolling> insert row cf cq 5 >> rolling> insert row cf cq 6 >> rolling> insert row cf cq 7 >> rolling> insert row cf cq 8 >> rolling> scan >> row cf:cq [] 8 >> row cf:cq [] 7 >> row cf:cq [] 6 >> row cf:cq [] 5 >> row cf:cq [] 4 >> row cf:cq [] 3 >> row cf:cq [] 2 >> >> This is exactly what I wanted to see. So I wrote a simple scanner >> program to read the table. Then I did another scan: >> >> rolling> scan >> row cf:cq [] 8 >> >> Where did the rest of the records go? >
