6. ( 2 )什么是文档型? A document database is, at its core, a key/value store with one major exception. Instead of just storing any blob in it, a document db requires that the data will be store in a format that the database can understand. The format can be XML, JSON, Binary JSON (MongoDB), or just about anything, as long as the database can understand it. 例如 --MongoDB >use taojin > db.user.find() { "_id" : ObjectId("4ec320a11d90d0521b973342"), "name" : "taojin", "pwd" : "123456" } /data/db 目录下 -rw------- 1 root root 64M Nov 18 14:05 taojin.0 -rw------- 1 root root 128M Dec 21 10:32 taojin.1 -rw------- 1 root root 16M Nov 18 14:05 taojin.ns