MongoDB 2.2 Index

 

• In mysql index has been learned and know to improve the query speed of the index
• mongodb also supported the index to improve query speed

Step one: create large amounts of data

• Execute the following code, insert 100,000 documents to the collection

for(i=0;i<100000;i++) {

    db.t1.insert({name:'test'+i, age:i})

}

Step two: Find data Performance Analysis

• Find the name is 'test10000' documents

db.t1.find({name:'test10000'})

• Use explain () command to query performance analysis

db.t1.find({name:'test10000'}).explain('executionStats')

• Which under executionStats executionTimeMillis an overall query time, in milliseconds
• Performance analysis results as shown below:

 

 

 Step Three: index

• Creating an index
• 1 for ascending, descending -1 for

. Db set .ensureIndex ({properties: 1})

db.t1.ensureIndex({name:1})

Step four: the index attribute query

• Above the same query, and the query performance analysis

db.t1.find({name:'test10000'}).explain('executionStats')

• Performance analysis results as shown below:

 

The index command

• The establishment of a unique index, a unique constraint functions to achieve

db.t1.ensureIndex({'name':1}, {'unique':true})

• Joint index, to establish an index of a plurality of attributes according to find () appears in the order

db.t1.ensureIndex({name:1, age:1}）

 

•  View all indexed documents

db.t1.getIndexes()

 

 

• Delete Index

db.t1.dropIndexes ( 'Index Name')