MongoDB管理练习

一、索引

1.插入10W条数据 文档内容为：{name:zs-i,age:1}

2016-06-07T14:35:57.041+0800 I CONTROL [initandlisten]

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

... db.person.insert({name:"zs"+i,age:i})

... }

WriteResult({ "nInserted" : 1 })

2.在属性name上创建索引

> db.person.ensureIndex({name:1})

{

"createdCollectionAutomatically" : false,

"numIndexesBefore" : 1,

"numIndexesAfter" : 2,

"ok" : 1

}

3.查看执行计划，观察使用索引和不使用索引的区别

建立索引前

> db.person.find({name:"zs"+10000}).explain()

{

"cursor" : "BasicCursor",

"isMultiKey" : false,

"n" : 1,

"nscannedObjects" : 100000,

"nscanned" : 100000,

"nscannedObjectsAllPlans" : 100000,

"nscannedAllPlans" : 100000,

"scanAndOrder" : false,

"indexOnly" : false,

"nYields" : 781,

"nChunkSkips" : 0,

"millis" : 30,

"server" : "weekend01:27017",

"filterSet" : false

}

建索引后

> db.person.find({name:"zs"+10000}).explain()

{

"cursor" : "BtreeCursor name_1",

"isMultiKey" : false,

"n" : 1,

"nscannedObjects" : 1,

"nscanned" : 1,

"nscannedObjectsAllPlans" : 1,

"nscannedAllPlans" : 1,

"scanAndOrder" : false,

"indexOnly" : false,

"nYields" : 0,

"nChunkSkips" : 0,

"millis" : 0,

"indexBounds" : {

"name" : [

[

"zs10000",

"zs10000"

]

]

},

"server" : "weekend01:27017",

"filterSet" : false

}

> db.person.find({name:"zs"+10000}).hint({name:1}).explain()

{

"cursor" : "BtreeCursor name_1",

"isMultiKey" : false,

"n" : 1,

"nscannedObjects" : 1,

"nscanned" : 1,

"nscannedObjectsAllPlans" : 1,

"nscannedAllPlans" : 1,

"scanAndOrder" : false,

"indexOnly" : false,

"nYields" : 0,

"nChunkSkips" : 0,

"millis" : 0,

"indexBounds" : {

"name" : [

[

"zs10000",

"zs10000"

]

]

},

"server" : "weekend01:27017",

"filterSet" : false

}

二、备份与恢复

1.中断备份与恢复

a.备份数据库test中的student

[root@weekend01 ~]# mongoexport -d test -c student -o studnet.json

connected to: 127.0.0.1

exported 0 records

b.删除数据库test中的student

> db.student.drop()

true

c.恢复数据库test中的student

导入其他数据

[root@weekend01 ~]# mongoimport --db test --collection student --file studnet.json

connected to: 127.0.0.1

2016-06-07T18:02:18.612+0800 check 0 0

2016-06-07T18:02:18.612+0800 imported 0 objects

2.运行时备份与恢复、

a.备份数据库test

[root@weekend01 ~]# mongodump --host 127.0.0.1:27017 -d test -o /tmp

connected to: 127.0.0.1:27017

2016-06-07T18:04:27.161+0800 DATABASE: test to /tmp/test

2016-06-07T18:04:27.167+0800 test.system.indexes to /tmp/test/system.indexes.bson

2016-06-07T18:04:27.167+0800 2 documents

2016-06-07T18:04:27.167+0800 test.person to /tmp/test/person.bson

2016-06-07T18:04:27.482+0800 100000 documents

2016-06-07T18:04:27.482+0800 Metadata for test.person to /tmp/test/person.metadata.json

b.删除数据库test

> db.dropDatabase()

{ "dropped" : "test", "ok" : 1 }

c.恢复数据库test

[root@weekend01 ~]# mongorestore --host 127.0.0.1:27017 -d test -directoryperdb /tmp/test/

connected to: 127.0.0.1:27017

2016-06-07T18:06:22.060+0800 /tmp/test/person.bson

2016-06-07T18:06:22.060+0800 going into namespace [test.person]

100000 objects found

2016-06-07T18:06:23.253+0800 Creating index: { key: { _id: 1 }, name: "_id_", ns: "test.person" }

2016-06-07T18:06:23.297+0800 Creating index: { key: { name: 1 }, name: "name_1", ns: "test.person" }

主要算法及程序清单

a.插入10W条数据

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

db.person.insert({name:"zs"+i,age:i})

}

b.查询name为zs10000的数据

db.person.find({name:"zs"+10000}).explain() --看效果，此时没建name索引

c.建立索引

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

d.查询name为zs10000的数据

db.person.find({name:"zs"+10000}).explain()

db.person.find({name:"zs"+10000}).hint({name:1}).explain() --看效果，此时已建name索引

1.中断操作 -- 像冷备

a.把数据库test中的student导出 --备份

mongoexport -d test -c student -o d:/student.json

mongoexport --db test --collection student --out /root/student1.json

b.删除test数据库中的student

db.student.drop()

c.导入数据（中断其他操作） --恢复

mongoimport --db test --collection student --file /root/student.json

mongoimport -d test -c student --file d:/student.json

2.运行时备份 --像热备 整库备份

a.导出数据库

mongodump --host 127.0.0.1:27017 -d test -o /root

b.删除整个数据库

db.dropDatabase()

c.运行时恢复

mongorestore --host 127.0.0.1:27017 -d test -directoryperdb /tmp/test

疑难小结

本次实验重在考察对mongoDB的操作，类似上个实验，本次实验中难题没有，都是些基本的操作，只要在明白其理论基础上加上多敲多练多想就会有很大收获。看着再简单，不动手永远不知道自己会碰到什么状况，所以还是要多动手练习。