Object Databases are on Market for more then 20 years now. Having a very hard time in being the first to fight SQL, the products are now extremely mature and industry proven. Object databases offer stunning capabilities and features which are unfortunately rarely known. Indeed several of the largest databases in the world are object databases. The talk will show the object database space, typical application scenarios and benefits.

MongoDB is an attempt to combine the best features of document-oriented datastores, key/value stores and RDBMSes. This talk presents MongoDB and gives an overview of it's architecture and features. We'll talk about what makes MongoDB different from some of the other NoSQL solutions as well as what use cases MongoDB is well-suited for. Questions will be encouraged throughout the talk.

Riak is an open-source licensed distributed key-value- and document-store developed by Basho Inc. Riak has all the features of state-of-the-art distributed KV-stores ranging from an HTTP/REST-based API to an integrated MapReduce framework and pluggable storage-engines.

Riak's unique contribution is its flexible query facilities. It's datastore can be queried by a simple description of a graph traversal process which is transformed into a chain of MapReduce steps at query-time. The result is a system with flexible data-extraction, -filtering and -processing possibilities that go beyond "traditional" MapReduce-enabled stores.

Riak's code base is small and clean such that is is easy to understand and extend its implementation. By this, it is both a great foundation for building own systems on top of Riak and a great learning resource for all things NoSQL.

CouchDB makes building web applications simpler. On top of that, it enables building distributed peer-to-peer applications that allow users to own their personal data and be in full control of the application use and code. CouchDB applications, or CouchApps, can live near the user on his/her local computers and devices as well as in the cloud on big hosted instances of CouchDB. The sharing aspect of CouchDB enables it to scale as far down as a mobile phone as well as up to multi-data-center sizes.

Redis is a simple yet incredibly powerful and wicked fast key-value database. Following an asynchronous storage model it kicks ACID out the door, focussing solely on data, speed and high throughput. Like Memcached it supports a range of basic datatypes, including strings, lists and sets, with the latter supporting atomic operations on their contents.

"If you’re concerned about scalability, any algorithm that forces you to run agreement will eventually become your bottleneck." Failure tolerant distributed key-value stores that provide strong consistency need to run an agreement protocol among a set of nodes. Such a protocol either involves much data to be sent among these nodes, in terms of messages, or high latency due to the number of communication steps between these nodes. Paxos is an example for a fault tolerant consensus algorithm used in a number of distributed key-value stores.

The presentation explains the theoretical background about Werner Vogels's claims about distributed key-value stores with strong consistency. It covers the CAP theorem as well as Paxos as an example for an agreement protocol of a fully decentralized key-value store.

Speaker's bio: Monika Moser is currently working as a Erlang/Ruby/Hadoop developer at nugg.ad. Before starting at nugg.ad she designed and implemented the transactional storage layer of Scalaris, a scalable, transactional, distributed key-value store written in Erlang, while working in research at Zuse Institut, Berlin following her graduation from Humboldt Universität.