http://ayende.comAyende @ RahienCopyright (C) Ayende Rahien 2004 - 2021 (c) 202660Eric, Document DB & Graph DB are similar, but not identical. Graph DB are optimized for graph operations, doc dbs aren't. http://ayende.com/4488/that-no-sql-thing-graph-databases#comment6http://ayende.com/4488/that-no-sql-thing-graph-databases#comment6Wed, 23 Jun 2010 15:29:49 GMTI'm not sure I understand... From everything I read, it seems to imply that a Document DB is suited to a database of largely "independent" objects which are aggregates. Document DB's are not well suited for relationships. But in this post, it's stating the exact opposite. It's actually creating a database of largely "dependent" objects. I thought this is exactly what a Document DB does not excel / or good at? Isn't this better suited to a Relational Database? Or am I missing something? When is it "ok" to use relationships and when is it not? Is there a general rule to this? I am really struggling with this. http://ayende.com/4488/that-no-sql-thing-graph-databases#comment5http://ayende.com/4488/that-no-sql-thing-graph-databases#comment5Wed, 23 Jun 2010 15:25:20 GMTI partially agree with you. You can easly implement a GraphDB-like model on top of any Document DBMS, but you would need also of special operators to walk and traverse graphs. I'm working to OrientDB. It's a NoSQL hybrid document-graph dbms with special operators for graph operations. The main difference is that you can query it using SQL language with some extension like: select from People where friends TRAVERSE(1,7) (name = 'Ayende' and surname = 'Rahien') This means get all the people that have any relationship of friends with you up to the 7th level of separation. bye, Lvc@ http://ayende.com/4488/that-no-sql-thing-graph-databases#comment4http://ayende.com/4488/that-no-sql-thing-graph-databases#comment4Thu, 20 May 2010 08:10:37 GMTG, I am prototyping a lot of things. :-) http://ayende.com/4488/that-no-sql-thing-graph-databases#comment3http://ayende.com/4488/that-no-sql-thing-graph-databases#comment3Fri, 07 May 2010 01:46:54 GMTDon't tell us you've written a graphdb extension to raven as well... ;-) http://ayende.com/4488/that-no-sql-thing-graph-databases#comment2http://ayende.com/4488/that-no-sql-thing-graph-databases#comment2Thu, 06 May 2010 23:31:26 GMTNot sure how many posts coming that are going to cover this topic but it's probably a good idea to list some of the leading open source social graph databases in this category: Neo4J appears to be the leading social graph db that everyone else compares themselves to: [http://neo4j.org/](http://neo4j.org/) Although Twitter invented and uses FlockDB so by that definition its also worth a look: [http://github.com/twitter/flockdb](http://github.com/twitter/flockdb) And because its relevant one of the latest big announcements coming out of Facebook was that they've opened their Graph db so you can access it using their Graph API and even connect your own digital content to it using the Open Graph Protocol: [blogs.neotechnology.com/.../...raph-databases.html](http://blogs.neotechnology.com/emil/2010/04/on-the-facebook-open-graph-and-graph-databases.html) http://ayende.com/4488/that-no-sql-thing-graph-databases#comment1http://ayende.com/4488/that-no-sql-thing-graph-databases#comment1Thu, 06 May 2010 22:49:28 GMT