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Subject: Re: Modeling Relationships and providing Transactional Integrity
From: Robert Samuel Newson <rnewson@apache.org>
In-Reply-To: <0D27F132-296F-4034-BB02-82E8453B5E87@couchbase.com>
Date: Wed, 16 Apr 2014 21:46:39 +0100
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To: user@couchdb.apache.org

_bulk_docs is not transactional at all. all_or_nothing:true used to be =
but the semantic changed for the reason Jens notes, it doesn=92t work in =
a sharded context. Now it simply forcibly introduces conflicts if it has =
to.

B.

On 16 Apr 2014, at 15:32, Jens Alfke <jens@couchbase.com> wrote:

>=20
> On Apr 15, 2014, at 8:59 PM, Suraj Kumar <suraj.kumar@inmobi.com> =
wrote:
>=20
>>>  - To modify an attribute that is involved in a relationship, a
>>>  "transactional update" API must be used. All the related documents =
for
>>>  those change(s), must also be submitted through this API =
"bulk_doc"-like
>>>  API (perhaps bulk_docs itself?).
>=20
> I don=92t think _bulk_docs will provide a transactional update even on =
a single shard/node =97 the semantics will be the same as issuing a =
bunch of individual PUT requests one after the other, i.e. someone else =
can sneak in and update a doc in between two of your updates. There are =
warnings about this in the API docs (at least there were in the old =
docs; haven=92t checked the new ones.)=20
>=20
> There used to be an =93all or nothing=94 mode to _bulk_docs a long =
time ago that did provide a transactional update, but apparently it was =
removed because it couldn=92t be supported in a clustered environment =
(BigCouch).
>=20
> [The usual disclaimer: I=92m not familiar with the code inside =
CouchDB, only its behavior.]
>=20
> =97Jens
>=20
> PS: Removing the dev@ group from the reply because (a) I=92m not =
subscribed to that, and (b) it=92s off-topic.