Hi Tito,
my Futon says sth like "Processed 0 of 4 changes (0%)" - and the # of
changes might differ from the # of docs (at least when the indexing is
started several times). Likewise, the Futon start page displays # of docs
and the updates seq (=# of changes). Could that be one explanation?
Because I'd be with you: a new view (or any change to a design doc for that
matter) means working all documents of the DB (all N as you put it),
passing each to the view server and producing the view. The views remember
which document a non-reduced row belongs to, but as emit can happen zero,
one, or several times that's not really an indication
I'm afraid I don't have the cookie cutter - but let us know
Best
Sebastian
On Tue, Oct 28, 2014 at 6:56 PM, Tito Ciuro <[email protected]> wrote:
> Hello Joan,
>
> I’m getting this information in two places:
>
> - Futon’s “Status” page
> - CouchDB’s /_active_tasks payload
>
> I know there are ~950,000 documents in the database. This numbers appears
> in the /_utils main page. What I don’t understand is why the total number
> of documents differ when the active tasks are reported via Status page or
> /_active_tasks. Each active task has a different total number of docs to be
> processed.
>
> Yes, Genesis case is the initial case where CouchDB hasn’t had the
> opportunity to index anything.
>
> Thanks,
>
> — Tito
>
> > On Oct 28, 2014, at 10:50 AM, Joan Touzet <[email protected]> wrote:
> >
> > Hi Tito,
> >
> > Can you explain where you're getting the "total count" from? Is this the
> total number of rows emitted by each view after all views have finished
> processing?
> >
> > What do you mean by "Genesis case" - do you mean building a view for the
> first time?
> >
> > Thanks,
> > Joan
> >
> > ----- Original Message -----
> > From: "Tito Ciuro" <[email protected] <mailto:[email protected]>>
> > To: [email protected] <mailto:[email protected]>
> > Sent: Tuesday, October 28, 2014 1:32:37 PM
> > Subject: How does indexing really work?
> >
> > Hello,
> >
> > I’m a bit confused about how CouchDB really works. I just launched Futon
> and see that the indexer is busy working on a design document. I have
> almost a million documents.
> >
> > A few minutes later, I see three more tasks appearing, all belonging to
> different design documents. No problem, except that the total count is all
> different:
> >
> > - design doc 1: ~950,000
> > - design doc 2: ~450,000
> > - design doc 3: ~313,000
> > - design doc 4: ~85,000
> >
> > Why are the total counts different? My understanding is/was that a
> database holds N documents. Each indexing function is passed a document
> which then gets compares whether it’s the doc_type it expects:
> >
> > function(doc) {
> > <
> http://wiki.apache.org/couchdb/Introduction_to_CouchDB_views#CA-1846e35e0e66fe65e7a443a2459a0272833e6152_2
> <
> http://wiki.apache.org/couchdb/Introduction_to_CouchDB_views#CA-1846e35e0e66fe65e7a443a2459a0272833e6152_2>>if
> (doc.Type == "customer") {
> > <
> http://wiki.apache.org/couchdb/Introduction_to_CouchDB_views#CA-1846e35e0e66fe65e7a443a2459a0272833e6152_3
> <
> http://wiki.apache.org/couchdb/Introduction_to_CouchDB_views#CA-1846e35e0e66fe65e7a443a2459a0272833e6152_3>>emit(doc._id,
> {LastName: doc.LastName, FirstName: doc.FirstName});
> > <
> http://wiki.apache.org/couchdb/Introduction_to_CouchDB_views#CA-1846e35e0e66fe65e7a443a2459a0272833e6152_4
> <
> http://wiki.apache.org/couchdb/Introduction_to_CouchDB_views#CA-1846e35e0e66fe65e7a443a2459a0272833e6152_4
> >>}
> > }
> >
> > In the Genesis case, I was assuming that each view would have to go
> through each document across the database and index its own doc_type.
> Basically, one round for each design document for N total documents. For
> example, if the database contains 100,000 documents and two design
> documents, there would be two active tasks listed:
> >
> > - _design/customers => index 100,000 documents
> > - _design/orders => index 100,000 documents
> >
> > Later on, the indexing would be partial and the delta (say 9,000 docs)
> would have to be reindexed by each view:
> >
> > - _design/customers => index 9,000 documents
> > - _design/orders => index 9,000 documents
> >
> > This doesn’t seem to be the case. I’d love to know how indexing really
> works.
> >
> > Thanks!
> >
> > — Tito
>
>
