mongodb 索引

mongodb的索引的创建方法；

db.collection.ensureIndex(keys,options) 在mongodb3.0版本后被弃用。

现在是db.collection.createIndex()的别名

db.colleciton.getIndexes()得到collection的所有的索引 （） 只能在3.0版本用

For MongoDB 3.0 deployments using the WiredTiger storage
engine, if you rundb.collection.getIndexes() from a version of the mongo shell
before 3.0 or a version of the driver prior to 3.0
compatible version, db.collection.getIndexes() will
return no data, even if there are existing indexes. For more information, see WiredTiger
and Driver Version Compatibility.

得到collection的所有索引：

db.people.getIndexes()

To return a list of all indexes on all collections in a database, usethe following operation in the

mongo shell:

db.system.indexes.find()