1. GRAPH DATABASES

2. GRAPH Databases http://www.neo4j.org/develop/example_data 4/11/2014dr. salih yurttaş 2

3. GRAPH Databases More than a Graph and a Database or a special database based on graph structure: Graph DatabaseGraph Database Files > Hierarchical > Network > Relational > Object- Oriented > Graph Database 4/11/2014dr. salih yurttaş 3

4. GRAPH Databases GraphGraph structures based on Graph in mathematics. Graph theory is the study graphs by computer science and mathematicians.Graph theory 4/11/2014dr. salih yurttaş 4

5. GRAPH Databases Node and links to computer scientists or vertex and edges in mathematics. 4/11/2014dr. salih yurttaş 5

6. GRAPH Databases Storage and retrieval through nodes and links. http://blog.octo.com/en/graph-databases-an-overview/ http://e-reality-database.blogspot.com/2010/06/graph- database-tutorial.html http://www.hascode.com/2012/01/neo4j-graph-database- tutorial-how-to-build-a-route-planner-and-other-examples/ 4/11/2014dr. salih yurttaş 6

7. GRAPH Databases Specifically, we will try to answer an important question — when to use a graph database and when not use one. The answer is not that obvious. - See more at: http://blog.octo.com/en/graph- databases-an-overview/#sthash.UT0aiQr1.dpufhttp://blog.octo.com/en/graph- databases-an-overview/#sthash.UT0aiQr1.dpuf What is a graph database? A graph database is a databases whose specific purpose is the storage of graph-oriented data structures. Thus it’s all about storing data as vertices and edges. By definition, a graph database is any storage solution where connected elements are linked together without using an index. The neighbors of an entity are accessible by dereferencing a physical pointer. There are several types of graphs that can be stored: from a “single-type” undirected graph to an hypergraph, including of course property graphs. - See more at: http://blog.octo.com/en/graph-databases-an- overview/#sthash.UT0aiQr1.dpuf http://blog.octo.com/en/graph-databases-an- overview/#sthash.UT0aiQr1.dpuf 4/11/2014dr. salih yurttaş 7

8. GRAPH Databases Hence a graph database meets the following criteria: Storage is optimized for data represented as a graph, with a provision for storing vertices and edges Storage is optimized for the traversal of the graph, without using an index when following edges. A graph database is optimized for queries leveraging the proximity of data, starting from one or several root nodes, rather than global queries Flexible data model for some solutions: no need to declare data types for vertices or edges, as opposed to the more constrained table-oriented model of a relational database Integrated API with entry points for the more classical algorithms of the graph theory (shortest path, Dijsktra, A*, betweenness, …) See more at: http://blog.octo.com/en/graph-databases-an- overview/#sthash.UT0aiQr1.dpufhttp://blog.octo.com/en/graph-databases-an- overview/#sthash.UT0aiQr1.dpuf 4/11/2014dr. salih yurttaş 8

9. GRAPH Databases http://www.neo4j.org/develop/example_data http://projects.spring.io/spring-data-neo4j/ 4/11/2014dr. salih yurttaş 9