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Date: Tue, 29 Jun 2010 11:01:40 -0700 (PDT)
From: Behrad Zari <behrad_zari@yahoo.com>
Subject: Re: View Efficency
To: user@couchdb.apache.org
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> However, I think the original question from=0A> Behrad still stands, is i=
t more efficient to emit multiple keys per=0A> document, or create multiple=
 views?=0A=0AMy own analysis was: when emting multiple keys per document, w=
e have more index =0Akeys, i.e. a bigger tree. Call it M*N indexes where M =
is number of emits per =0Adocument and N is number of docs emitted! Since q=
uerying a B+ tree is logaritmic =0Ato the number of indexes, we MAY compare=
 Log(N) with Log(M*N) with base of tree =0Ablock sizes! and Since M is not =
that big in real applications, I don't think =0Aemiting multiple keys per d=
oc will give much more poor performance in quering =0Athe view in comparisi=
on to one emit per document. Take that In the later =0Ascenario we may want=
 to call multiple views and merge the results!=0A=0AAnother unclarified thi=
ng for me is the situation where we emit array keys (i.e. =0A[key1, key2,..=
.] ). I don't know about how that affects query time. Is the couch =0Abehav=
ior like single value keys?=0A=0AI don't know about CouchDB implementation =
specifics such as determining block =0Asize,... So I'd like CouchDB men can=
 clarify these situations.=0A=0A--Behrad=0A=0A=0A
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