MongoDB London UG, April 2011 - MongoDB Introduction

Transcript

1. A short introduction to MongoDB
   Russell Smith
   Friday, 20 April 12
   

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2. /usr/bin/whoami
   • Russell Smith
   • Consultant for UKD1 Limited
   • Specialising in helping companies going through rapid growth
   • Help with code, architecture, infrastructure, devops, sysops, capacity
   planning, etc
   • <3 gearman, mongodb, neo4j, mysql, kohana, riaksearch, php, debian
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3. What is MongoDB
   • A scalable, high-performance, open source, document-oriented
   database.
   • Stores JSON like documents
   • Indexible on any attributes (like MySQL)
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4. Getting started...
   • Try out the interactive shell at www.mongodb.org (then click try!)
   • Download and install - http://www.mongodb.org/downloads
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5. Basics
   • Common things you do in MySQL or another RDBMS;
   • Insert
   • Select (aka find)
   • Update
   • Delete (aka remove)
   • Index
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6. Create
   • Creating ‘tables’, or in MongoDB terms collections, is not usually
   necessary
   • Ditto for databases
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7. Insert
   • db.test.insert({hello: ‘world’});
   • This insert the document {hello: ‘world’} into the test collection
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8. Let’s check it
   • In MongoDB we find documents rather than SELECTing them...
   • db.test.find()
   • this is the equivalent of SELECT * FROM test;
   • it will return the document we previously inserted
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9. Updates
   • Let’s update the document to say from Russell
   • db.test.update(, )
   • db.test.update({hello: ‘world’}, {hello: ‘from Russell’})
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10. Delete?
    • db.test.remove()
    • Lets remove the last document
    • db.test.remove({hello: ‘from Russell’})
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11. Drop
    • If you no longer want an entire collection, you can drop it which
    removes all the data and indexes;
    • db.test.drop()
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12. Indexes
    • For performance it’s usually a good idea to index your collections.
    • How and which columns depends on what queries you are doing - you
    can get help with this by using ‘explain’ much like in MySQL.
    • db.test.ensureIndex({hello:1})
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13. Further reading
    • I’ve only brushed on the details, but this should be enough to get you
    interested / started with MongoDB. Some of the missing stuff;
    • Updates can also push, set, increment, decrement, etc - http://bit.ly/
    gEfKOr
    • Indexes can be across multiple keys, 2D (geo) and asc / desc - http://
    bit.ly/hpK68Q
    • SQL -> Mongo chart - http://bit.ly/ig1Yfj
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