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Push databases: A better way to build realtime ...

Push databases: A better way to build realtime apps

Jorge Silva

July 08, 2015
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  1. Push databases A better way to build realtime apps Bay

    Area OpenSource Palo Alto, CA July 8, 2015
  2. Realtime apps • More and more apps are built to

    be realtime • Users have come to want and expect this behavior in their apps • Building realtime apps is hard
  3. Building realtime apps is hard • You can keep everything

    in a single server • You can poll the database to keep track of updates • You can publish updates through 
 a message broker
  4. Building realtime apps is hard • All solutions present a

    tradeoff between scalability and complexity • It’s hard to keep track of state in 
 realtime architectures
  5. What is RethinkDB? • Open source database for building realtime

    web applications • NoSQL database that stores schemaless JSON documents • Distributed database that is easy to scale
  6. Push Database • Subscribe to change notifications from database queries

    (changefeeds) • No more polling — the database pushes changes to your app • Reduce the amount of plumbing needed to stream live updates
  7. Push Database • Having your database push changes keeps your

    database as the central source of truth • Having a central source of truth simplifies your architecture
  8. Push Database RethinkDB is an excellent database for: • Collaborative

    web and mobile apps • Multiplayer games • Streaming analytics apps • Connected devices
  9. Introduction to ReQL • ReQL embeds natively into your programming

    language • Compose ReQL queries by chaining commands
  10. Additional ReQL Features • Geospatial indexing for location- based queries

    • Date and time functions • Support for storing binary objects • Execute http requests using r.http
  11. Changefeeds • The changes command returns a cursor that receives

    updates • Each update includes the new and old value of the modified record
  12. Changefeeds r.table("users").changes() r.table("users") .insert({name: "Bob"}) Changefeed output: { new_val: {

    id: '362ae837-2e29-4695-adef-4fa415138f90', name: 'Bob', ... }, old_val: null }
  13. Changefeeds r.table("users").changes() r.table("users") .get("362ae837-2e29-4695-adef-4fa415138f90") .update({name: "Bobby"}) Changefeed output: { new_val:

    { id: '362ae837-2e29-4695-adef-4fa415138f90', name: 'Bobby' }, old_val: { id: '362ae837-2e29-4695-adef-4fa415138f90', name: 'Bob' } }
  14. Summary • Keeping track of state in realtime apps is

    hard • RethinkDB solves this problem by pushing changes to your app • In the future, we'll see more database that use the push model