couchdb-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Mark Hahn <m...@hahnca.com>
Subject Re: following fast doc updates
Date Wed, 26 Sep 2012 17:04:35 GMT
>> I have been working on a scheme that relies on tracking every change.

>To do what?

I have a sort of pub-sub.  The client (through a wbsocket) can ask to be
notified on changes.  The subscription can be for just part of a doc.  For
example a product doc may be followed to watch for just price changes.  The
same doc may be followed by a different subscription to watch for product
spec changes.  (made up example).

Before now I've just been publishing the record to everyone on any doc
change.  This causes a lot of unnecessary traffic and what's worse is that
client code does a lot of work updating the DOM and other things way more
often than necessary, causing ugly things to happen.

> Why not storing a change as a  new doc?

This would change the _id which would break whatever linking there is
between records.

On Tue, Sep 25, 2012 at 11:46 PM, Benoit Chesneau <bchesneau@gmail.com>wrote:

> On Sep 25, 2012 8:32 PM, "Mark Hahn" <mark@hahnca.com> wrote:
> >
> > > The _changes feed only ever shows leaf revisions
> >
> > AARRGGHH.  I am so screwed.  I have been working on a scheme that relies
> on
> > tracking every change.
> To do what?
>
> And as everyone knows there is normally no way to
> > find out what changed in a doc.  I am going to have to add a history of>
> changes to each doc which it not only wasteful, but a pain to implement.
>
> Why not storing a change as a  new doc?
> >
> > Thanks for taking the trouble to give me bad news.
> >
> >
> > On Tue, Sep 25, 2012 at 10:19 AM, Adam Kocoloski <kocolosk@apache.org
> >wrote:
> >
> > > On Sep 24, 2012, at 5:16 PM, Mark Hahn <mark@hahnca.com> wrote:
> > >
> > > > If I update a particular doc multiple times rapidly, is each update
> > > > guaranteed to show up in a continuous changes feed?  I am worried
> that
> > > the
> > > > change feed will be optimized to just show the latest value of a doc
> with
> > > > multiple updates.  This would break my logic.
> > >
> > > Your worries are justified.  The _changes feed only ever shows leaf
> > > revisions (i.e., latest updates to branches of the edit tree).
>  Regards,
> > >
> > > Adam
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message