NeDB SpeedMemory footprint 介绍
Node.js 实现的嵌入式数据存储，可以部分或全部替代sqlite数据库。可以当内存数据库使用也可本地存储。
NEDB采用非常灵活的查询方式，让你几乎可以忘记他是非关系数据库：
(1) 可以使用正则查询
(2) and or where 大于 小于 排序等
(3) 索引
数据存储采用JSON新式，可以深度查询。
eg:
// Let's say our datastore contains the following collection
{ _id: 'id5', completeData: { planets: [ { name: 'Earth', number: 3 }, { name: 'Mars', number: 2 }, { name: 'Pluton', number: 9 } ] } }
db.find({ "completeData.planets.0.name": "Earth" }, function (err, docs) { // docs contains document 5 // If we had tested against "Mars" docs would be empty because we are matching against a specific array element });
语法和MongoDB非常相似.
Speed
-
Insert: 5,950 ops/s
-
Find: 25,440 ops/s
-
Update: 4,490 ops/s
-
Remove: 6,620 ops/s
Memory footprint
A copy of the whole database is kept in memory. This is not much on the
expected kind of datasets (20MB for 10,000 2KB documents). If requested, I’ll
introduce an option to not use this cache to decrease memory footprint (at the
cost of a lower speed).
缺点：数据加载在内存中进行操作，不适合内存非常紧张的应用。目前作者没有给出细腻度的内存控制方法。