This document provides an overview of NoSQL and CouchDB. It discusses different types of NoSQL databases like key-value, graph, and document-oriented databases. It then focuses on CouchDB, explaining that it is written in C and Erlang, supports ACID properties, master-master replication, and uses JSON and HTTP with a RESTful API. Examples are given of CRUD operations using HTTP requests. It also discusses CouchDB's views using MapReduce and describes CouchDB's advantages like simplicity, flexibility, and backups, with disadvantages around performance.

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. ??????