Life in a matrix Life in a matrix

http://en.citizendium.org/wiki/NoSQL

1. Transaction

1) 기존 트랜잭션 기준: ACID

- Atomicity

- Consistency

- Isolation

- Durability

2) NoSQL 의 트랜잭션: BASE

- Basically Available

- Soft state

- Eventually Consistent

2. CAP theorem

A distributed system can support only two of the following characteristics

- Consistency

- Availability

- Partition tolerance

3. NoSQL Database type

1) Column Store: each storage block contains data from only one column

   ex) Hadoop/Hbase: Yahoo, Facebook

         Ingres VectorWise

2) Document Store: stores documents made up tagged elements

  ex) CouchDB, MongoDB

     => JSON (JavaScript Object Notation)

3) Key-Value Store: Hash table of keys

  ex) Project-Voldemort, MemCacheDB

* SQL Database

 - predefined schema

 - standard definition and interface language

 - tight consistency

 - well defined semantics

* NoSQL Database

 - No predefined schema

 - per-product definition and interface language

 - getting an answer quickly is more important than getting a correct answer

WG2_N1537_SQL_Standard_and_NoSQL_Databases 2011-05.pdf