Text: http://www.scribd.com/doc/83624536/Couch

1. Привет!

2. NoSQL
&
CouchDB
Епифанов Иван

3. SQL

4. SQL
MySQL
PostgreSQL
Oracle
MSSQL

5. NoSQL

6. Key-Value:
Redis
Membased
Tarantool
Tokyo cabinet (DBM)

7. key -> ?????

8. session_id =>
{
“serialized”:”data”
}

9. GRAPH:
Neo4j
InfiniteGraph

10. Вася
ID
ID
ID
ID
Петя ID
ID
Коля

11. Document-oriented:
MongoDB
CouchDB

12. {
"_id": "5b8c0893e90316c578af172e073ed132",
"type": "speech",
"title": "Hello NoSQL",
"author" "iSage",
"text": "$this",
"tags": [ "nosql",
"mongo",
"couch",
"whisky",
"boring"
],
"listeners": [ {
"name": "Dmitry",
"position": "manager"
},
{
"name": "Sergey",
"position": "team lead"
},
...
]
}

13. MapReduce!

14. [
document, => map()
document, => map()
document, => map()
document, => map()
]

15. map = function(document) {
for (tag in document.tags)
{
emit(tag, 1 );
}
};

16. [
“tagname1”: 1,
“tagname2”: 1,
“tagname3”: 1,
...
“tagnameN”: 1
]

17. reduce = function( key , value ) {
var total = 0;
for (var i = 0;i < values.length;i++) {
total += values[i];
}
return total;
};

18. [
“tagname1”: 56,
“tagname2”: 42,
“tagname3”: 13,
...
“tagnameN”: 4
]

19. 36
21
15 5 16
2 13 4 1 5 11

21. CouchDB

22. CouchDB
C + Erlang

23. CouchDB
C + Erlang
ACID

24. CouchDB
C + Erlang
ACID
master-master

25. CouchDB
C + Erlang
ACID
master-master
JSON

26. CouchDB
C + Erlang
ACID
master-master
JSON
HTTP

27. CouchDB
C + Erlang
ACID
master-master
JSON
HTTP
RESTful

28. POST http://couchdb/database/
{
“name”: “oh hai”,
“text”: “well, hello there”
}
<= 5b8c0893e90316c578af172e073ed132

29. GET
http://couchdb/database/5b8c0893e90316c578af
172e073ed132
<=
{
“_id”: “5b8c0893e90316c578af172e073ed132”
“name”: “oh hai”,
“text”: “well, hello there”
}

30. PUT
http://couchdb/database/5b8c0893e90316c578af
172e073ed132
{
“name”: “oh hai”,
“text”: “well, hello there!”
}
<= 5b8c0893e90316c578af172e073ed132

31. DELETE
http://couchdb/database/5b8c0893e90316c578af
172e073ed132
<= 200 OK

32. {
"_id": "_design/users",
"language": "javascript",
"views": {
"by_mail": {
"map":
"function(doc) {
if (doc.type=='user')
emit(doc.email,doc);
}"
},
"by_oauth2_id": {
...
},
"by_oauth1_id": {
...
}
}
}

33. + Прост
+ Понятен
+ JSON
+ Гибкая авторизация
+ ACID
+ full master replication, sharding
+ HTTP/Erlang Server
+ cp -r /my/database/ ~/couch_backups/
+ no structure – no versions!

34. + Прост
+ Понятен
+ JSON
+ Гибкая авторизация
+ ACID
+ full master replication, sharding
+ HTTP/Erlang Server
+ cp -r /my/database/ ~/couch_backups/
+ no structure – no versions!
- медленнее mongo, redis, etc.
- http = slow
- MapReduce(MapReduce(MapReduce()))

35. BONUS

37. ??????