MongoDB Learning Note III (MONGODB index operation and performance test)

Chapter III index operations and performance testing The importance of indexes under big data is not much to say.The following test used a MongoDB client tool Robomongo, you can choose to download on the Internet. Inserting test data

Insert 1 million test data first

 for (var i=1;i<1000000; i++) {  var person={name: "Jack" +i,age:i,address:["Henan", "Wuhan"],course:[{name: "Shuxue", Score:i  },{Name: "Wuli", Score:i}]}db. DemoTest.Person.insert (person)}

Performance analysis functions (explain)

MongoDB gives us a keyword called "explain" for performance analysis.

Perform the query analysis as follows:

Db. DemoTest.Person.find ({Name: "jack5784124"}). Explain ()

从我们可以看出在没有建立索引的情况下，查询的时间大约是是615毫秒。

Create an index

Db. TestCollection.Person.ensureIndex ({name:1})

-----1 indicates the index in ascending alphabetical order

Inquire

As we can see from the graph, the query time becomes about 2 milliseconds and the performance is increased by hundreds of times times.

Unique index

As with SQL Server, you can create a unique index, and duplicate key values cannot be inserted naturally, and the use in MongoDB is as follows:

Db. TestCollection.Person.ensureIndex ({name:1},{"unique": True} )

Combined index

Sometimes our query is not single-condition, may be multi-conditional, then we can set up a composite index to speed up the query.

Db. TestCollection.Person.ensureIndex ({name:1,age:1})

Delete Index

Db. TestCollection.Person.dropIndex ("index name")

MongoDB Learning Note III (MONGODB index operation and performance test)