Packet query and processing for MongoDB

Delete name+latin+status+sysname duplicate data in synonymslist table
Db.synonymsList.aggregate ([
{
$group: {
_id: {name: "$name", Latin: "$latin", Status: "$status", SysName: "species2000"},
Count: {$sum: 1},//get Total
Dups: {$addToSet: ' $_id '}//staging _id to set
}
},{
$match: {count:{$gt: 1}}//only to find duplicate data greater than 1
}
],{
allowdiskuse:true//the hard disk cache is used because the data exceeds 16M
}). ForEach (function (DOC) {
Doc.dups.shift ();//Remove any one of the repeating data from the set as a reserved
Db.synonymsList.remove ({_id: {$in: Doc.dups}});//Remove the remaining duplicate data
})