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From Jukka Zitting <jukka.zitt...@gmail.com>
Subject Re: AW: writing a new DocumentStore implementation
Date Mon, 20 Jan 2014 14:41:39 GMT

On Mon, Jan 20, 2014 at 7:59 AM, Thomas Mueller <mueller@adobe.com> wrote:
> I think it should be relatively easy to extend the Segment storage to
> store to a read from a database. However, I'm not sur if that's currently
> planned.

Yes, actually Dominique was just working on something like that in
OAK-1333. That extension allows a reference to a binary in an external
Data- or BlobStore to be used instead of the actual binary contents in
a SegmentMK value record.

However, as you mention, the design philosophy of the SegmentMK is
quite different from the MongoMK (DocMK?) or the old MicroKernelImpl
from which the BlobStore originates, so while it's possible to use the
same blob backend also with SegmentMK, doing so goes a bit against the
design goals. By storing binaries directly within segments, the
SegmentMK simplifies garbage collection (no need to track nodes and
binaries separately for the purpose of GC) and makes it possible to
support efficient update and append operations on existing binaries
(should we want to expose such a feature).


Jukka Zitting

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