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From Calvin Metcalf <calvin.metc...@gmail.com>
Subject Re: Checkpointing on read only databases
Date Sun, 13 Apr 2014 17:31:34 GMT
Though currently we have the opposite problem right if we delete the target
db? (this on me brain storming)

Could we store last rev in addition to last seq?
On Apr 13, 2014 1:15 PM, "Dale Harvey" <dale@arandomurl.com> wrote:

> If the src database was to be wiped, when we restarted replication nothing
> would happen until the source database caught up to the previously written
> checkpoint
>
>    create A, write 5 documents
>    replicate 5 documents A -> B, write checkpoint 5 on B
>    destroy A
>    write 4 documents
>    replicate A -> B, pick up checkpoint from B and to ?since=5
>    .. no documents written
>
>
> https://github.com/pouchdb/pouchdb/blob/master/tests/test.replication.js#L771is
> our test that covers it
>
>
> On 13 April 2014 18:02, Calvin Metcalf <calvin.metcalf@gmail.com> wrote:
>
> > If we were to unilaterally switch to checkpoint on target what would
> > happen, replication in progress would loose their place?
> > On Apr 13, 2014 11:21 AM, "Dale Harvey" <dale@arandomurl.com> wrote:
> >
> > > So with checkpointing we write the checkpoint to both A and B and
> verify
> > > they match before using the checkpoint
> > >
> > > What happens if the src of the replication is read only?
> > >
> > > As far as I can tell couch will just checkout a checkpoint_commit_error
> > and
> > > carry on from the start, The only improvement I can think of is the
> user
> > > specifies they know the src is read only and to only use the target
> > > checkpoint, we can 'possibly' make that happen automatically if the src
> > > specifically fails the write due to permissions.
> > >
> >
>

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