2. Michael Hackstein
@mchacki
‣ ArangoDB Core Team
‣ Web Frontend
‣ Graph visualisation
‣ Graph features
!
!
‣ Organiser of cologne.js
‣ Master’s Degree
(spec. Databases and
Information Systems)
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3. Once upon a time…
‣ Use a SQL-based database
‣ Implement logic to transform your data into table format
‣ Create / Generate complex queries
‣ Implement logic to transform data from table format in required
format
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5. Main Categories of NoSQL DBs
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Key/Value Store Document Store Graph Database
Source: Andrew Carol
Polyglot Persistence
6. Key-Value Store
‣ Map value data to unique string keys (identifiers)
‣ Treat data as opaque (data has no schema)
‣ Can implement scaling and partitioning easily due to simplistic
data model
‣ Key-value can be seen as a special case of documents
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7. Document Store
‣ Normally based on key-value stores (each document still has a
unique key)
‣ Allow to save documents with logical similarity in “databases”
or “collections”
‣ Treat data records as attribute-structured documents (data is
no more opaque)
‣ Often allow querying and indexing document attributes
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9. Polyglot Persistence
‣ „Use the right tool for the job“
‣ If you have structured data with some differences
‣ Use a document store
‣ If you have relations between entities and want to efficiently
query them
‣ Use a graph database
‣ If you manage the data structure yourself and do not need
complex queries
‣ Use a key-value store
‣ If you have structured data where all objects have equal
attributes
‣ Use a relational database
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11. Benefits & Costs
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‣ Native mapping of data into DB
‣ DB optimized
‣ Queries are tailored for your
data format
‣ Focus on writing business logic
‣ Several technologies involved
‣ Experts required for each
‣ Administration effort is huge
‣ Application logic has to
interface with several sources
‣ Data has to be stored
redundantly and has to be kept
in sync
13. Multi Model Database
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‣ Can store several kinds of data models:
‣ Acts as a key-value store
‣ Acts as a document store
‣ Stores graphs natively
‣ Delivers query mechanisms for all data models
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‣ a multi-model database (document store & graph database)
‣ is open source and free (Apache 2 license)
‣ offers convenient queries (via HTTP/REST and AQL)
‣ offers high performance and is memory efficient
‣ uses JavaScript throughout (V8 built into server)
‣ doubles as a web and application server (Foxx)
‣ offers many drivers for a wide range of languages
‣ is easy to use with web frontend and good documentation
‣ enjoys good professional as well as community support
‣ and recently added sharding in Version 2.0.
15. Different query interfaces
Different scenarios require different access methods:
‣ Query a document by its unique id / key:
GET /_api/document/users/12345
‣ Query by providing an example document:
PUT /_api/simple/by-example
{ "name": "Michael", "age": 26 }
‣ Query via AQL:
FOR user IN users
FILTER user.active == true
RETURN {
name: user.name
}
‣ Graph Traversals
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16. Why another query language?
‣ Initially, we implemented a subset of SQL's SELECT
‣ It didn't fit well
‣ UNQL addressed some of the problems
‣ Looked dead
‣ No working implementations
‣ XQuery seemed quite powerful
‣ A bit too complex for simple queries
‣ JSONiq wasn't there when we started
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17. Other Document Stores
‣ MongoDB uses JSON/BSON as its “query language”
‣ Limited
‣ Hard to read & write for more complex queries
‣ CouchDB uses Map/Reduces
‣ It‘s not a relational algebra, and therefore hard to generate
‣ Not easy to learn
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18. ArangoDB Query Language (AQL)
‣ We came up with AQL mid-2012
‣ Declarative language, loosely based on the syntax of XQuery
‣ Other keywords than SQL so it's clear that the languages are
different
‣ Implemented in C and JavaScript
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19. Extendable through JS
‣ Dynamic Language that enriches ArangoDB
‣ Multi Collection Transactions
‣ Graph Traversals
‣ Cascading deletes/updates
‣ Aggregate data from multiple queries into a single response
‣ Data-intensive operations
‣ Actions, Foxx, Application Server
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20. Application Server / Action Server
‣ ArangoDB can answer arbitrary HTTP requests directly
‣ You can write your own JavaScript functions (“actions”) that
will be executed server-side
‣ Includes a permission system
‣ Build your own API rapidly using the Foxx framework
!
!
➡ You can use it as a database or as a combined database/
application server
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23. Join our growing community
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.. working on the geo index, the full text
search and many APIs: Ruby, Python, PHP,
Java, D, ...
24. Summary
‣ Multi-Model databases simplify database setup
‣ Cross-out transformation of data-formats
!
‣ ArangoDB
‣ Based on web standards: HTTP, REST, JSON
‣ Flexible querying: Documents, Graphs in the same language
‣ Reduce Server <-> Database communication:
‣ Define your own API using Foxx
‣ Execute data-intensive code within the database
‣ You can even use ArangoDB as our application server
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25. 25
Thank you
!
‣ Further questions?
‣ Follow me on twitter/github: @mchacki
‣ Or write me a mail: mchacki@arangodb.org
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