I am working on a RSS reader application. And I need to find a backend database. I want the database be embedded because I don\'t want the users to install a database server
There is no straight forwarding way to use MongoDB as an embedded library in terms of a well-reusable library. Eliot - head of 10gen - spoke of "it would be nice to have one" - but there is nothing available that could be reused in a sane way.
(I don't yet have 50 rep points to comment on, and build upon, the accepted answer; otherwise I would, sorry!)
You can embed MongoDB in your OEM solution but there are two things to consider:
It is written in C++, so if you are coding in a different language you might need to write a wrapper that launchers the database process separately.
MongoDB is licensed under Gnu AGPL-3.0 which is a copy left server license. The accepted answer, and the Google group quote, both correctly state that this would normally force you to also be AGPL licensed. However, they MongoDb states that the intention of the license is to allow refinements to their code to be submitted back, and that your product will remain separate. This makes me think that the normal copy left rules don't apply.
The goal of the server license is to require that enhancements to MongoDB be released to the community. Traditional GPL often does not achieve this anymore as a huge amount of software runs in the cloud. For example, Google has no obligation to release their improvements to the MySQL kernel – if they do they are being nice.
To make the above practical, we promise that your client application which uses the database is a separate work. To facilitate this, the mongodb.org supported drivers (the part you link with your application) are released under Apache license, which is copyleft free. Note: if you would like a signed letter asserting the above promise please request via email.
Source: http://www.mongodb.org/display/DOCS/Licensing
According to the Google Group, yes it can, but it doesn't cover how exactly.
Yes, but it isn't pretty and will force your app to be AGPL licensed. If you are interested take a look at how the tools handle the --dbpath option.
Source: http://groups.google.com/group/mongodb-user/browse_thread/thread/463956a93d3fb734?pli=1
If you're using .NET, one option might be RavenDB, which is a document database, and can be embedded.
Please checkout https://github.com/Softmotions/ejdb This project being developed to resolve this issue.
How about Couchbase Lite? It's an open source, embeddable document database. While it can function as a standalone document database, its real value is in its ability to synchronize with remote document databases. It may be aimed at iOS / Android, but it can run on anything with a JVM.
https://github.com/couchbase/couchbase-lite-java
Looks like a lot of OEMs are trying to get Mongo on to their hardware and devices for real-time processing. A link from MongoDBs website