Slides from my LiveDB presentation at Cornerstones devsum conference 2011.

1. Introducing liveDB
Build faster systems faster
Robert Friberg, robert@devrex.se
Twitter: @robertfriberg, @livedomain, #livedb
http://livedb.devrex.se/
liveDB

2. Prevalent System Architecture
Clients
Client
liveDB
.NET Process Memory Disk
Engine
In-memory
Object
Model
Transaction Log
Synchronized execution Snapshot.0
Pass queries and
commands
Command
serialization
Client
Snapshot.1
Snapshot.N

3. The prevalent hypothesis
 Your data will fit in available RAM
 99% of all OLTP database are 1TB or less
--Stonebraker, VoltDB
liveDB

4. Eric Schmidt, Google CEO
At Google we found it costs less money and it is more
efficient to use DRAM as storage as opposed to hard
disks.
Three minutes with Google's Eric Schmidt , CNN.COM
liveDB

5. What is liveDB?
 A native .NET in-memory database engine
 Full ACID support
 Embedded engine free to use for any purpose
 Supports any data representation
liveDB

6. The NoSQL revolution
 RDBMS paradigm is shaking
 Alternative data representation, document, graph, key/value, etc
 Support large scale databases
 LiveDB focuses on
 Memory vs. Disk
 Freedom of representation
 Facebook is not the common case
liveDB

7. Relational Database Prison
 Relational model formulated 1969
 Designed to address limitations non-existent today – disk access
 A relational model is just one of many possible datarepresentations
 Primitive stored procedure language
 O/R Mapping adds to the pain
liveDB

8. O/R mapping vs Command/Query pattern
 O/R mapping is based on CRUD pattern
 CRUD is a specialization of Request/response
 Command/Query is more general (superset)
 You can do CRUD with Command/Query but not the other way around
liveDB

9. Business arguments
 Reduced time to market
 Lower TCO for software systems
 Reduced development time up to 40%
 Operations (no rdbms)
 Licensing (no rdbms)
 Faster systems
liveDB

10. Developer benefits
 Model is pure .NET types and collections
 representational freedom
 DAL and downwards is eliminated
 No object/relational mapping
 No relational modeling
 No T-SQL programming
 Debugging
 Version control
 Supports DDD, TDD
liveDB

11. Simple API
liveDB

12. Start your engines!
var db = Engine.Load<MyModel>(path);
db.Execute(command);
var c = db.Execute(m => m.Customers.GetById(42));
...
var cmd = SetPasswordCommand(c.Id, newPassword);
db.Execute(cmd);
db.Close();
liveDB

13. Demo!
 http://roxsux.devrex.se/
 Coding a simple model
 Commands and queries
 Hosting the engine
 See blog for more info: http://livedb.devrex.se/
liveDB

14. Drawbacks
 Model must fit in RAM
 Load time (start up and rollback)
 Versioning issues
 .NET Only (Json possible)
 No magical indexing (yet)
liveDB

15. Gotchas
 No external dependencies from commands
 Don’t modify the model with query
 Rollback is expensive
 Don’t manipulate model out of context
 Dont rely on reference equality
 Results are not direct references
liveDB

16. References
 Prevalent System Architecture
 prevayler.org, java project from 2003, alive and kicking
 Bamboo.Prevalence .NET 1.1, dead project?
 VoltDB
liveDB

17. Thank you!
Robert Friberg, Devrex
Twitter: @robertfriberg, @livedomain, #livedb
http://livedb.devrex.se/
liveDB