CouchDB talk about it's potential, it's unique features, how map/reduce works (simplified) and just how awesome CouchDB really is. Rock on!

1. CouchDB
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2. CouchDB
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Sander van de Graaf
svdgraaf

3. RELAX...

4. PERFORM LIKE A PR0N STAR

5. TOPICS
• NoSQL
• CouchDB in a nutshell
• Querying
• map/reduce
• Fulltext search
• CouchApps

6. NOSQL

7. IT’S A MOVEMENT

8. 1998

17. Carlo Strozzi

18. NOSQL == Not Only SQL

19. “[The NoSQL movement] departs from the relational
model altogether, it should therefore have been called
more appropriately ‘NoREL’, or something to that
effect.”
- Carlo Strozzi

20. CouchDB
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26. NUTSHELL

27. SPEED

28. APPEND ONLY

29. NO REPAIR NEEDED

30. COMPACTING

31. HTTP SERVER

32. CAP

33. CouchDB
CAP

34. CouchDB
EVENTUALLY CONSISTENT

35. FULL REST API

36. REST
• GET • SELECT
• PUT • UPDATE
• POST • INSERT
• DELETE • DELETE
• COPY • ...

38. JSON
{
total_rows: 2,
offset: 0,
rows: [
{
id: '_design/foobar',
key: '_design/foobar',
value: { rev: '5-982b2fc36835715b2aae54609b5d5f1e' }
},
{
id: 'f0e1fd96eb6e094f74dda8d949000a6a',
key: 'f0e1fd96eb6e094f74dda8d949000a6a',
value: { rev: '1-86bca407fce8234a63c90ff549b56b10' }
},
]
}

39. REPLICATION

40. CouchDB
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41. CouchDB
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42. CouchDB
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43. CouchDB
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44. CouchDB
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45. US NL
CouchDB
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46. Laptop Desktop
CouchDB
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CouchDB
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CouchDB
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47. P2P WEB

51. QUERYING

52. SELECT * FROM documents WHERE id = 123
GET /documents/123

53. SELECT * FROM documents WHERE id = 123
GET /documents/123
PUT /documents/123
POST /documents/123
DELETE /documents/123
etc.

54. MAP/REDUCE

56. INPUT
IP Bytes
212.122.174.13 18271
212.122.174.13 191726
212.122.174.13 198
74.119.8.111 91272
74.119.8.111 8371
212.122.174.13 43

57. MAPPER => REDUCER
IP Bytes
18271
191726
212.122.174.13
198
43
91272
74.119.8.111
8371

58. AFTER REDUCE
IP Bytes
212.122.174.13 210238
74.119.8.111 99643

59. MAP/REDUCE
SELECT COUNT(foo)
FROM documents
WHERE 1
GROUP BY foo;

60. MAP/REDUCE

61. MAP/REDUCE
function(doc) {
emit(doc.foo, doc);
}

62. MAP/REDUCE

63. MAP/REDUCE
function(keys, values, rereduce) {
return sum(values);
}

64. MAP/REDUCE

65. COUCHDB-LUCENE
http://github.com/rnewson/couchdb-lucene

66. CONFIG
[external]
fti=/path/to/python /path/to/couchdb-lucene/tools/couchdb-external-hook.py
[httpd_db_handlers]
_fti = {couch_httpd_external, handle_external_req, <<"fti">>}

67. http://127.0.0.1:5984> GET /foobar/_design/foobar

68. _DESIGN
{
_id: '_design/foobar',
_rev: '8-03a6bc983c721b1cc0ae4b461326bc31',
language: 'javascript',
views: {
foo: { map: 'function(doc) {n emit(doc.foo,1);n}',
reduce: 'function(keys, values, rereduce) {return sum(values);}' }
}
}

69. _DESIGN
{
_id: '_design/foobar',
_rev: '8-03a6bc983c721b1cc0ae4b461326bc31',
language: 'javascript',
views: {
foo: { map: 'function(doc) {n emit(doc.foo,1);n}',
reduce: 'function(keys, values, rereduce) {return sum(values);}' }
},
fulltext: {
by_subject: {
index:"function(doc) { var ret=new Document(); ret.add
(doc.subject); return ret }"
},
}
}

70. _DESIGN
function(doc) {
var ret=new Document();
ret.add(doc.subject);
return ret
}

71. _DESIGN
function(doc) {
var result = new Document();
result.add(doc.subject, {"field":"subject", "store":"yes"});
result.add(doc.content, {"field":"subject"});
result.add(new Date(), {"field":"indexed_at"});
return result;
}

72. http://127.0.0.1:5984> GET /foobar/_fti/_design/foo/by_subject?q=foobar

73. http://127.0.0.1:5984> GET /foobar/_fti/_design/foo/by_subject?q=foobar

74. COUCHAPPS
http://github.com/couchapp/couchapp

75. “Distributed, scalable, web
applications you say?
omgwtfbbq!?!1!!!11!1!eleven”

76. _attachments

77. CouchDB
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78. COUCHAPP PUSH HTTP://LOCALHOST:5984/MYDB

79. LISTS
http://127.0.0.1:5984> GET /relax/_design/relax/_list/posts/all/foobar
HTTP/1.1 200 OK
Vary: Accept
Transfer-Encoding: chunked
Server: CouchDB/0.11.0 (Erlang OTP/R13B)
Etag: "DZZ19EPLWLHI89K1FOW9DGFT5"
Date: Sun, 11 Jul 2010 09:55:42 GMT
Content-Type: text/html
<h1>ponies</h1><p>rock!</p>

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81. CouchDB
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82. COUCHDBX
http://janl.github.com/couchdbx/

83. Q?