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From: Nils Breunese <N.Breunese@vpro.nl>
To: "user@couchdb.apache.org" <user@couchdb.apache.org>
Date: Tue, 22 Mar 2011 19:53:34 +0100
Subject: RE: Relationships Of Complex Documents In Document Databases
Thread-Topic: Relationships Of Complex Documents In Document Databases
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Although I think CouchDB is great, maybe using a relational database isn't =
such a strange idea if you want to model a lot of relationships... :o)

On the other hand I don't necessarily see a problem with storing tasks as d=
ocuments with a username field in them and for instance creating a view tha=
t lists tasks by username.

Nils.
________________________________________
Van: Ryan Zec [basire@gmail.com]
Verzonden: dinsdag 22 maart 2011 16:28
Aan: user@couchdb.apache.org
Onderwerp: Relationships Of Complex Documents In Document Databases

I have been looking at a number of document databases (RavenDB, CouchDB,
MongoDB) and there are two things about them that I really like and makes m=
e
what to incorporate them as much as possible and that is the schema-less
natural (not that they are schema-less per-say but that it is a very
flexible schema that is much easier to change than ones with RDBMS) and the
fact there is a lot less impedance mismatch when mapping the database data
to code.

There have a been a number of things that I have found that have prevented
me from using a document database because I find I need these things all th=
e
time.  Some of them I have found solutions for like unique fields.  While
document databases don't directly support this feature, a work around that
is acceptable is creating another document with the email is the document i=
d
and then inserting the user if the insert on the email document was
successful however there are there is one big thing that I don't think
document database can provide me from my searching.

That feature is relationships with complex documents.  One of my projects I
wanted to use a document database for is a project management system.  The
issue with this is that there are a lot of places where I need relationship=
s
with large objects (and multiple relationships within one document).  When
it come to something like a task or a user, those are complex documents and
having the document embedded would not be a good thing as data mismatch wit=
h
these items can't happen.  Now if I just reference the document then am I
really getting any benefit from using a document database because now I am
probably going to have a lot more queries that I need to run compared to a
relational database.

While I was hopping to have most of my data be stored into a document
database, the more I look at it, it seems like most of the data needs to be
in a RDBMS.  Am I correct in assuming this type of relationship needs a
RDBMS or am I un-aware of how this can be accomplished in a document
database.
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