[英]MongoDB, Mongoose - Slow query when fetching 10k+ documents
I have a MongoDB database with 10-12k documents in a collection and I'm experiencing really slow queries when attempting to fetch all documents, like this: 我有一个包含10-12k文档的MongoDB数据库,在尝试获取所有文档时遇到的查询速度非常慢,如下所示:
Sales.find()
.where('author').equals(author)
.where('date').gt(startDate.unix()).lt(endDate.unix())
.exec(function(err, results) {
callback();
});
This query fetches around 10.5k documents and it takes 1000-1300ms to execute. 此查询提取大约10.5k文档,执行时需要1000-1300ms。 I tried removing the "where" conditions - it only makes it slower (more documents fetched?).
我尝试删除“where”条件 - 它只会使它变慢(获取更多文档?)。
Does the problem come from Mongoose, MongoDB, JavaScript or Node? 问题来自Mongoose,MongoDB,JavaScript还是Node? I used to run PHP/MySQL database and it was 10-20 times faster in similar conditions, like fetching 10k+ rows of data.
我以前运行PHP / MySQL数据库,在类似条件下速度提高10-20倍,比如获取10k +行数据。 What am I doing wrong?
我究竟做错了什么?
EDIT 编辑
Sales schema: 销售架构:
var salesSchema = new Schema({
author: String,
kind: String,
productID: String,
description: String,
date: String,
amount: String,
transactionID: {
type: String,
unique : true
}
});
Query result from the RoboMongo desktop client: 来自RoboMongo桌面客户端的查询结果:
db.getCollection('sales').find({}).explain()
executionTimeMillis: 46
nReturned: 10359
The problem came from Mongoose. 问题来自Mongoose。 By default, find() will return documents as Mongoose Documents, which costs a lot.
默认情况下,find()会将文档作为Mongoose Documents返回,这会花费很多。 By adding lean() to the query, documents are returned as plain JavaScript objects and for this case of 10k+ returned documents, the query time got reduced 3-5 times .
通过向查询添加lean(),文档作为纯JavaScript对象返回,对于10k +返回文档的情况,查询时间减少了3-5倍 。
Sales.find()
.where('author').equals(author)
.where('date').gt(startDate.unix()).lt(endDate.unix())
.lean()
.exec(function(err, results) {
callback();
});
Read more here: http://www.tothenew.com/blog/high-performance-find-query-using-lean-in-mongoose-2/ 在这里阅读更多内容: http : //www.tothenew.com/blog/high-performance-find-query-using-lean-in-mongoose-2/
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