mongo 的 find和aggregate

db.d.find({},{'Detail':0}).sort({'RecordCreateTime':-1}).skip(400).limit(20)

报异常：
“Executor error during find command: OperationFailed: Sort operation used more than the maximum 33554432 bytes of RAM. Add an index, or specify a smaller limit.”

解决：
1、改用aggregate ，并将allowDiskUse=true ，为false有RAM 100M限制，

db.d.aggregate([            { $match:{}},            { $project:{'Word':1} },            {'$sort':{'RecordCreateTime':-1}},            {'$skip':1000},            {'$limit':30}        ],{allowDiskUse:true})

2、当然不加排序sort 也可以解决