CouchDB: map-reduce in Erlang

Question

How can I write map-reduce functions in Erlang for CouchDB? I am sure Erlang is faster than JavaScript.

Can't be a coincidence: http://browsertoolkit.com/fault-tolerance.png — shoosh, Jul 23 '09 at 08:24

Fu. · Answer 1 · 2009-07-23T22:27:15.613

25

pmap(F, L) ->
    Parent = self(),
    Pids = [spawn(fun() ->
                     Parent ! {self(), F(X)}
                  end) || X -> L],
    [receive {Pid, Res} -> Res end || Pid < - Pids].

I believe I did, Bob.

edited Jul 23 '09 at 22:27

answered Jul 23 '09 at 21:26

Fu.

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Needs the cartoon pasted in there for added value :D – madlep Jul 25 '09 at 05:47
Lulz...consider my afternoon laugh provided for. – Joshua Noble Jul 27 '09 at 18:56

score 16 · Accepted Answer · answered Jul 23 '09 at 08:24

16

You can do so using erlview, which is within the top ten hits on Google for "couchdb erlang view" and is listed on the CouchDB wiki page for other-language view servers.

answered Jul 23 '09 at 08:24

Jim Puls

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With the next release of CouchDB erlang views will be built in. You won't even have to download and setup erlview to make it work. – Jeremy Wall Aug 21 '09 at 03:38
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CouchDB 0.10 (released October 2009) and later support Erlang views natively. A good writeup is at http://blog.echolibre.com/2010/02/couchdb-custom-erlang-map-functions/ – JasonSmith Jun 12 '10 at 07:51

CouchDB: map-reduce in Erlang

2 Answers2