MongoDB Grand Rapids RUG

INTRO • Built For Speed • Document/Collection Oriented • Dynamic Queries and Indexes • Replication and Failover

GREAT FOR • Websites • Caching • High volume, low value • High scalability • Storage of program objects and json

NOT AS GREAT FOR • Highly transactional • Ad-hoc business intelligence • Problems requiring SQL

INSTALLATION • mkdir -p /data/db • download pre-built for OSX and unzip to /usr/local/ • cp -R /usr/local/pathtomongo/bin /usr/local/bin

DATABASE • same concept as mysql • made up of collections

COLLECTION • Think table, but with no schema • For grouping documents into smaller query sets (speed) • Eachtop level entity in your app would have its own collection (users, articles, etc.) • Indexable by one or more key

DOCUMENT • Stored in a collection, think record or row • Can have _id key that works like primary keys in MySQL • Two options for relationships: subdocument or db reference

QUERYING • db.collection.find({‘first_name’: ‘John’}) # finds all Johns • db.collection.find({‘first_name’: /^J/}) # regex • db.collection.find_first({‘_id’:1}) # finds first with _id of 1 • db.collection.find({‘age’: {‘$gt’: 21}}) # finds possible drinkers • db.collection.find({‘author.first_name’:‘John’}) # subdocument • db.collection.find({$where:‘this.age >= 6 && this.age <= 18’})

MORE QUERYING • $in, $nin, $all, $ne, $gt, $gte, $lt, $lte, $size, $where • :ﬁelds (like :select in active record) • :limit, :offset for pagination • :sort ascending or descending [[‘foo’, 1], [‘bar’, -1]] • count and group (uses map/reduce)

HOW DO YOU USE IT WITH RUBY • mongo-ruby-driver http://github.com/mongodb/mongo-ruby- driver • activerecord adapter http://github.com/mongodb/ activerecord-mongo-adapter • mongorecord http://github.com/mongodb/mongo- activerecord-ruby

NUNEMAPPER (MONGOMAPPER) • Mongo is not MySQL • DSL for modeling domain should also teach you Mongo • It sounded fun • Almost ﬁnished and sitting in private GitHub repo

FEATURES • Typecasting • Create and Update with single or multiple • Callbacks(ActiveSupport Callbacks) • Delete and Destroy and _all counterparts • Validations (using my fork of validatable) • Find: id, ids, :all, :ﬁrst, :last • Connection and database • Associations (incomplete) can differ per document

EXAMPLE class User include MongoMapper::Document key :name, String, :required => true, :length => 5..100 key :email, String, :required => true, :index => true key :age, Integer, :numeric => true key :active, Boolean, :default => true one :address many :articles end class Address include MongoMapper::EmbeddedDocument key :street, String key :city, String key :state, String, :length => 2 key :zip, Integer, :numeric => true, :length => 5 end

RANDOM AWESOMENESS • Capped collections (think memcache, actually used for replication) • Upserts db.collection.update({‘_id’:1}, {‘$inc’:{‘views’:1}}) • Multikeys (think tagging and full text search) • GridFS and auto-sharding

John Nunemaker http://orderedlist.com http://railstips.org Links http://www.10gen.com http://mongodb.com

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MongoDB Grand Rapids RUG

by John Nunemaker on Jun 03, 2009

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MongoDB Grand Rapids RUG — Presentation Transcript