Re: [bailey-developers] SF.net SVN: bailey: [17] trunk/src

[Ning L. <nin...@gm...>]

On Mon, Mar 31, 2008 at 6:03 PM, Doug Cutting <cu...@ap...> wrote:
>  The naive approach is simply to db.getDoc() and check the version, no?

Yes. The current implementation does that. I was worried about
its performance because I thought db.getDoc() means retrieving
a full document. But you mentioned the semantics of retrieving
the outline of a document. That would work. It's time to have
db.getDoc(id) and db.getDoc(id, fields)?

>  If the existing version is newer, then we ignore.  Note that deletes
>  come with a version, so if the indexed version is newer than the
>  deletion, we ignore the delete, just like an add.

Do we index a delete?

>  Yes, in general.  We might be able to avoid it when copying new ranges
>  into a node, if the log is de-duplicated.  But for general
>  synchronization I think we always need to check versions.
>
>  So it might be worth optimizing the doc->version implementation.  So the
>  method to add might be db.getVersion(String id). This doesn't make sense
>  for end users, so should be added to the Database API we use in a node,
>  not to the base abstract class.

So we have index deletes and keep them?

>  Yes, that sounds reasonable.  I was just questioning whether this
>  belongs the top-level Database API, or rather just in
>  HostToHostProtocol.  I just want to hide as much as we can from
>  end-users, so that we can more freely re-arrange things underneath later.
>
>  Eventually the top-level API might add a method like getDocs(String[]
>  ids, String[] fields), which looks similar, but has a different purpose.

I see.

Ning