RethinkDB is an open-source NoSQL database designed for building scalable, real-time web applications, allowing developers to use changefeeds for live updates without the need for polling. Its query language, ReQL, supports various operations and is easy to integrate with multiple programming languages. The database architecture promotes a push access model, simplifying state management in real-time apps while facilitating collaborative functionalities.

1. Theopen-sourcedatabase
fortherealtimeweb.

2. Source: http://googledrive.blogspot.com/2014/06/newdocssheetsslides.html

4. Building realtime apps is hard
It’s hard to keep track of state in realtime architectures.
Realtime web
app server
Realtime web
app server
Mobile app server
Message queue
Database cluster
Queues communicate
state and messages
between servers.

5. Building realtime apps is hard
Polling data to keep track of updates is cumbersome.
Adding new realtime functionality keeps getting harder.
Routing realtime messages vs. broadcasting messages.
It’s hard to keep track of state in realtime architectures.

6. What is RethinkDB?
• Open source database for
building realtime web apps
• NoSQL database that stores
schemaless JSON documents
• Distributed database that is easy
to scale

7. Built for realtime apps
RethinkDB lets you subscribe to change notifications
on database queries.
r.table(‘users’).changes() # Opens a changefeed on a table
Subscribe to changes on the ‘users’ table:
No more polling: the database pushes changes to your app,
with a live stream of updates.

8. Built for realtime apps
Changefeeds let you build scalable, realtime apps.
Realtime web
app server
Realtime web
app server
Mobile app server
RethinkDB cluster
Each server subscribes to
a RethinkDB changefeed.
Servers are stateless, and
scale easily (just open a
changefeed!)

9. Built for realtime apps
Changefeeds let you build scalable, realtime apps:
• Collaborative web and mobile apps
• Multiplayer games
• Streaming analytics apps
• Realtime marketplaces
• Connected devices

10. Querying RethinkDB
r.table(‘users’)
.pluck(‘last_name’)
.distinct().count()
Count unique last names with ReQL:

11. Querying RethinkDB
r.table(‘users’)
.pluck(‘last_name’)
.distinct().count()
Count unique last names with ReQL:
Access a database table

12. Querying RethinkDB
r.table(‘users’)
.pluck(‘last_name’)
.distinct().count()
Count unique last names with ReQL:
Isolate a document property

13. Querying RethinkDB
r.table(‘users’)
.pluck(‘last_name’)
.distinct().count()
Count unique last names with ReQL:
Consolidate duplicate values

14. Querying RethinkDB
r.table(‘users’)
.pluck(‘last_name’)
.distinct().count()
Count unique last names with ReQL:
Count the number of items

15. Understanding ReQL
RethinkDB’s query language embeds natively into
your programming language.
• Compose queries by chaining
• Queries are executed and
distributed on the server
• Python, Ruby, JavaScript, and 20+
other languages supported

16. What can you do with ReQL?
• Transformations: map, orderBy, skip, limit,
slice
• Aggregations: group, reduce, count, sum,
avg, min, max, distinct, contains
• Documents: row, pluck, without, merge,
append, difference, keys, hasFields, spliceAt
• Writing: insert, update, replace, delete
• Control: forEach, range, branch, do,
coerceTo, expr

17. Changefeeds work on queries
r.table(‘user_profiles’)
.filter(r.row(‘likes’).gt(30))
.changes()
Get notified when a user profile gets over 30 likes:

18. Changefeeds work on queries
r.table(‘user_profiles’)
.filter(r.row(‘likes’).gt(30))
.changes()
Get notified when a user profile gets over 30 likes:

19. Changefeeds work on queries
r.table(‘user_profiles’)
.filter(r.row(‘likes’).gt(30))
.changes()
Get notified when a user profile gets over 30 likes:
Clients can subscribe to this
realtime stream of updates.

20. Example: realtime questions
questions.rethinkdb.com
Let’s play with changefeeds:
Check out the code yourself: github.com/mglukhovsky/realtime-questions

21. Example: realtime questions
Questions server Questions server Dashboard server
RethinkDB cluster
Changes are pushed to each stateless app server.

22. Advancing the realtime web
The push access model simplifies realtime architecture.
One source of truth makes it easy to manage state.
RethinkDB is the first database for the realtime web.
Polling for data is slow, cumbersome, hard to maintain.

24. A realtime, open-source backend
for JavaScript apps

25. Horizon makes it easy to quickly prototype
your web and mobile app, and then scale it
to millions of users.

26. Learn more about RethinkDB
Get started: rethinkdb.com/install
Read the docs: rethinkdb.com/docs
Follow on Twitter: @rethinkdb