/explain-db

Primary LanguageMakefile

explain-db

mongodb: explain

準備好除了 DB 之外的工具：

https://github.com/mongodb/homebrew-brew

  • 先加入 mongodb 的 formula
  • mongo shell
  • db command-line tools (mongoimport, mongoexport, mongodump, etc)
brew tap mongodb/brew
brew install mongodb-community-shell
brew install mongodb-database-tools

運行 mongodb：

make restart-mongo

匯入資料：

data source from: https://www.w3resource.com/mongodb-exercises/

$ unzip data/restaurants.zip
Archive:  data/restaurants.zip
  inflating: restaurants.json

$ mongoimport --host 127.0.0.1 -d test -c restaurants --file restaurants.json
2021-10-31T20:55:34.621+0800    connected to: mongodb://127.0.0.1/
2021-10-31T20:55:34.774+0800    3772 document(s) imported successfully. 0 document(s) failed to import.

使用 mongo shell 連進去：

mongo
  • 預設 connecting to: mongodb://127.0.0.1:27017/?compressors=disabled&gssapiServiceName=mongodb

explore explain()

> use test
> db.restaurants.find().limit(1).pretty()
...
> let queryPlanner = db.restaurants.explain()
> let executionStats = db.restaurants.explain("executionStats")

create index

> db.restaurants.createIndex( {borough: 1} )
{
	"createdCollectionAutomatically" : false,
	"numIndexesBefore" : 1,
	"numIndexesAfter" : 2,
	"ok" : 1
}