Couchdb
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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.
![{
"_id": "5b8c0893e90316c578af172e073ed132",
"type": "speech",
"title": "Hello NoSQL",
"author" "iSage",
"text": "$this",
"tags": [ "nosql",
"mongo",
"couch",
"whisky",
"boring"
],
"listeners": [ {
"name": "Dmitry",
"position": "manager"
},
{
"name": "Sergey",
"position": "team lead"
},
...
]
}](https://image.slidesharecdn.com/couchdb-120303025204-phpapp02/85/Couchdb-12-320.jpg)
![[
document, => map()
document, => map()
document, => map()
document, => map()
]](https://image.slidesharecdn.com/couchdb-120303025204-phpapp02/85/Couchdb-14-320.jpg)
![[
“tagname1”: 1,
“tagname2”: 1,
“tagname3”: 1,
...
“tagnameN”: 1
]](https://image.slidesharecdn.com/couchdb-120303025204-phpapp02/85/Couchdb-16-320.jpg)
![reduce = function( key , value ) {
var total = 0;
for (var i = 0;i < values.length;i++) {
total += values[i];
}
return total;
};](https://image.slidesharecdn.com/couchdb-120303025204-phpapp02/85/Couchdb-17-320.jpg)
![[
“tagname1”: 56,
“tagname2”: 42,
“tagname3”: 13,
...
“tagnameN”: 4
]](https://image.slidesharecdn.com/couchdb-120303025204-phpapp02/85/Couchdb-18-320.jpg)
Couchdb
- 1. Привет!
- 2. NoSQL & CouchDB Епифанов Иван
- 3. SQL
- 4. SQL MySQL PostgreSQL Oracle MSSQL
- 5. NoSQL
- 6. Key-Value: Redis Membased Tarantool Tokyo cabinet (DBM)
- 7. key -> ?????
- 8. session_id => { “serialized”:”data” }
- 9. GRAPH: Neo4j InfiniteGraph
- 10. Вася ID ID ID ID Петя ID ID Коля
- 11. Document-oriented: MongoDB CouchDB
- 12. { "_id": "5b8c0893e90316c578af172e073ed132", "type": "speech", "title": "Hello NoSQL", "author" "iSage", "text": "$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
- 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. ??????