!everything
about
Graph Databases
To SQL or NOSQL
is that the question ?
Ye olde RDBMS's
etc etc
Key-value db's
{key, value}
(although, more complex data structures are often built on top of this...)
Comes in many flavors:
kv Cache
kv Store
kv Store (Eventually Consistent)
kv Store (Ordered)
...
Column family db's
Uses 'tuples' to store data, almost always distributed
Document-oriented db's
<Article>
<Author>
<FirstName>Bob</FirstName>
<Surname>Smith</Surname>
</Author>
<Abstract>This paper concerns....</Abstract>
<Section n="1"><Title>Introduction</Title>
<Para>...
</Section>
</Article>{
"_id" : 1,
"name" : { "first" : "John", "last" : "Backus" },
"contribs" : [ "Fortran", "ALGOL", "Backus-Naur Form", "FP" ],
"awards" : [
{
"award" : "W.W. McDowell Award",
"year" : 1967,
"by" : "IEEE Computer Society"
},
{ "award" : "Draper Prize",
"year" : 1993,
"by" : "National Academy of Engineering"
}
]
}To be Schemaful or Schemaless...
Graph db's
Comparing the apples and PINEAPPLES...
| Data Model | Performance | Scalability | Flexibility | Complexity | Functionality |
|---|---|---|---|---|---|
| Key–Value Store | high | high | high | none | variable (none) |
| Column-Oriented Store | high | high | moderate | low | minimal |
| Document-Oriented Store | high | variable (high) | high | low | variable (low) |
| Graph Database | variable | variable | high | high | graph theory |
| Relational Database | variable | variable | low | moderate | relational algebra |
So, graphs you say...
Thanks, Leonhard !
Leonhard Euler, 1707-1783
Seven bridges of königsberg
#1: make a model (graph)
#2: count the nodes and relations as you 'walk the graph'
So what's a graph then ?
Formally, a graph is just a collection of vertices and edges
or
a set of nodes and the relationships that connect them.
Why Neo4J ?
Neo4j is a highly scalable, robust (fully ACID) native graph database. Neo4j is used in mission-critical apps by thousands of leading startups, enterprises, and governments around the world.
(labeled) Property Graph
nodes and relationships,
+ properties. (and labels)
Cypher
MATCH (m:Movie)<-[:ACTS_IN]-(actor)-[:ACTS_IN]->(movie)
RETURN movie.title, collect(actor.name), count(*) AS count
ORDER BY count DESC ;MATCH (node) -[:RELATIONSHIP]- (node)MATCH (you:Person { name:"Your Name" }), (kevin:Person { name:"Kevin Bacon" }),
path = shortestPath((you)-[*..6]-(kevin))
RETURN path() -[]- ()Don't take my word for it,
try it yourself, it's easy !
Stand Back!
i'm switching to DEMO mode..
Graph Databases
By maderskog
