Datomic JFall 2012

Introduction to Datomic for JFall 2012

Transcript

1. Datomic a time-aware NoSQL database Daan van Berkel
2. Agenda •Agenda •Background •Introduction •Demonstration •Exploration •Conclusion
3. Background A people without the knowledge of their past history, origin and culture is like a tree without roots. - Marcus Garvey
4. Background http://en.wikipedia.org/wiki/Moore%27s_law Moore's Law: the number of transitors on integrated circuits doubles approximately every two years
5. Background http://en.wikipedia.org/wiki/Moore%27s_law
6. Background http://www.jcmit.com/memoryprice.htm
7. Background http://www.jcmit.com/memoryprice.htm
8. Background Cost drives design if memory is expensive update in place this loses information http://en.wikipedia.org/wiki/Relational_database
9. Background Properties of RDBS ACID •Atomic •Consistent •Isolated •Durable
10. Background Properties of RDBS ACID •Atomic •Consistent •Isolated •Durable "All or nothing" if one part fails, it should fails entirely
11. Background Properties of RDBS ACID •Atomic •Consistent •Isolated •Durable "I am the law" data should always meet the constraints set out by the design
12. Background Properties of RDBS ACID •Atomic •Consistent •Isolated •Durable "Play nice" concurrent executions should not be aware of each other presence
13. Background Properties of RDBS ACID •Atomic •Consistent •Isolated •Durable "Stay put" Changes once made should be permanent
14. Background A lot of responsibility for RDBMS •Query •Storage •ACID
15. Background
16. Background NoSQL •Distributed •Not Relational ◦Document ◦Key-Value
17. Background NoSQL •Distributed •Not Relational ◦Document ◦Key-Value Loses ACID principle http://localhost:8080
18. Introduction
19. Introduction •Clojure ◦Functional ▪Lisp ▪Scheme ◦JVM ▪Integration •Datomic ◦NoSQL ◦Time aware
20. Introduction http://www.datomic.com/
21. Introduction http://www.datomic.com/
22. Introduction http://www.datomic.com/
23. Introduction http://www.datomic.com/
24. Introduction Datomic stores Datoms Representation of a fact •entity •attribute •value •transaction
25. Introduction Datomic stores Datoms Representation of a fact •entity •attribute •value •transaction Examples [Daan ate pancakes T37] [Daan drank milk T37] [Daan ate pizza T51] [Daan wentTo gym T79] [Mink wentTo gym T79]
26. Introduction Change database by •Adding •Retracting in a transaction Preserve history [:db/id 37 :likes "fish"] [:db/retract 37 :likes "fish"]
27. Introduction Query by [:find ... in ... where ...] •Variables •Inputs •Clauses [:find ?e :in $ :where [?e :likes "fish"]]
28. Demonstration •BeanShell •Seattle Communities Community - name - url - neighbourhood - category - org type - com type Org Type - community - commercial - nonprofit - personal Com Type - email-list - twitter - facebook-page - blog - website - wiki Neighbourhood - name - district District - name - region
29. Exploration Transaction •Query over time [ :find ?v ?t :in $, ?a :where [?a :account/balance ?v ?t] ]
30. Exploration Invoking functions all community names with a name less than "C" [ :find ?n :where [?e :community/name ?n] [(.compareTo ?n "C") ?res] [(< ?res 0)] ]
31. Exploration Full Text Search [ :find ?e ?n :in $, ?k :where [(fulltext $ :community/name ?k) [[ ?e ?n ]]] ]
32. Exploration Custom rules [[:twitter ?c] [?c :community/type :community.type/twitter]] [ :find ?n :in $ % :where [?c :community/name ?n](:twitter ?c)] ]
33. Exploration Time awareness db.asOf(date) db.since(date) db.with(transaction)
34. Conclusion Datomic •NoSQL •Time Aware •State of the Art •Accessible API •Optimized reads •Highly Concurrent
35. Questions Contact daan.vanberkel@luminis.eu @daan_van_berkel dvberkel https://github.com/dvberkel/jfall2012-datomic http://goo.gl/4ENKb