Mongo db
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The document discusses MongoDB and its features. It covers getting started with MongoDB using the Ruby driver, using rich documents with complex objects and dynamic queries, map reduce for aggregation, indexing, GridFS for file storage, replication with replica sets, auto-sharding, pros and cons, common use cases, and provides links for additional resources.
![Ruby driver
require 'rubygems'
require 'mongo'
@db = Mongo::Connection.new.db("blog")
@blogposts = @db['blogposts']
Monday, 27 September 2010](https://image.slidesharecdn.com/mongodb-100927035637-phpapp02/85/Mongo-db-4-320.jpg)
![“complex objects”
blogpost = {
:title => "My First Post",
:author => {:name => "Jane"},
:comments => [{ :by => "Abe", :text => "First" },
{ :by => "Ada", :text => "Good post" }]
}
@blogposts.save(blogpost)
Monday, 27 September 2010](https://image.slidesharecdn.com/mongodb-100927035637-phpapp02/85/Mongo-db-8-320.jpg)
![“complex objects”
blogpost = {
:title => "My First Post",
:time => Time.now.utc,
:author => {:name => "Jane"},
:views => 0,
:languages => ["English", "Italian", "Spanish"],
:comments => [{ :by => "Abe",
:text => "First", :vote => 1, :date => Time.now.utc }]
}
@blogposts.save(blogpost)
Monday, 27 September 2010](https://image.slidesharecdn.com/mongodb-100927035637-phpapp02/85/Mongo-db-9-320.jpg)
![dynamic queries
@blogposts.find( { "author.name" => "Jane" } )
@blogposts.find( { "author.name" => /^J/ } )
@blogposts.find( { :time =>
{'$lte' => Time.utc(1970,1,1)} } )
@blogposts.find( { :languages => {'$in' =>
["English", "Italian"] } } )
Monday, 27 September 2010](https://image.slidesharecdn.com/mongodb-100927035637-phpapp02/85/Mongo-db-10-320.jpg)
![find and modify!
cmd = BSON::OrderedHash.new
cmd[:findandmodify] = 'blogposts'
cmd[:query] = { :title => "My First Post" }
cmd[:update] = { '$set' =>
{ :title => "My First Post updated"}}
DB.command(cmd)
Monday, 27 September 2010](https://image.slidesharecdn.com/mongodb-100927035637-phpapp02/85/Mongo-db-11-320.jpg)
![map reduce
def self.target_for_report(report)
collections = DB['targets'].group(['metric'],
{ :report_type => report.report_type,
:project_name => report.project },
{ 'docs' => [] },
"function(doc, prev) { prev.docs.push(doc); }");
end
Monday, 27 September 2010](https://image.slidesharecdn.com/mongodb-100927035637-phpapp02/85/Mongo-db-16-320.jpg)
![indexes
@blogposts.create_index([[ "comments.by" , Mongo::ASCENDING ]]);
db.blogposts.ensureIndex( { "comments.by" : 1 } );
@blogposts.create_index([[ :languages , Mongo::ASCENDING ]]);
@blogposts.create_index([[ :time , Mongo::DESCENDING ]]);
@blogposts.create_index([[ :author , Mongo::ASCENDING, true ]]);
@blogposts.create_index(
[[ "comments.vote" , 1,], [ "comments.date", -1 ]]);
Monday, 27 September 2010](https://image.slidesharecdn.com/mongodb-100927035637-phpapp02/85/Mongo-db-18-320.jpg)
Mongo db
- 1. MongoDB Forward Tech Away Day 24 Sep 2010 toni@forward.co.uk Monday, 27 September 2010
- 2. 1 Get to know MongoDB Monday, 27 September 2010
- 4. Ruby driver require 'rubygems' require 'mongo' @db = Mongo::Connection.new.db("blog") @blogposts = @db['blogposts'] Monday, 27 September 2010
- 5. a simple document post = { :time => Time.now.utc, :title => "Simple Post", } @blogposts << blogpost Monday, 27 September 2010
- 6. When we call #save: 1. Adds an _id 2. Serialise to BSON 3. socket.send() Monday, 27 September 2010
- 7. 2 Use rich documents Monday, 27 September 2010
- 8. “complex objects” blogpost = { :title => "My First Post", :author => {:name => "Jane"}, :comments => [{ :by => "Abe", :text => "First" }, { :by => "Ada", :text => "Good post" }] } @blogposts.save(blogpost) Monday, 27 September 2010
- 9. “complex objects” blogpost = { :title => "My First Post", :time => Time.now.utc, :author => {:name => "Jane"}, :views => 0, :languages => ["English", "Italian", "Spanish"], :comments => [{ :by => "Abe", :text => "First", :vote => 1, :date => Time.now.utc }] } @blogposts.save(blogpost) Monday, 27 September 2010
- 10. dynamic queries @blogposts.find( { "author.name" => "Jane" } ) @blogposts.find( { "author.name" => /^J/ } ) @blogposts.find( { :time => {'$lte' => Time.utc(1970,1,1)} } ) @blogposts.find( { :languages => {'$in' => ["English", "Italian"] } } ) Monday, 27 September 2010
- 11. find and modify! cmd = BSON::OrderedHash.new cmd[:findandmodify] = 'blogposts' cmd[:query] = { :title => "My First Post" } cmd[:update] = { '$set' => { :title => "My First Post updated"}} DB.command(cmd) Monday, 27 September 2010
- 12. upsert @blogposts.update({:title => "My First Post"}, blogpost, { :upsert => true }) Monday, 27 September 2010
- 13. update @blogposts.update({:title => "My First Post"}, blogpost) @blogposts.update( {:title => "My First Post"}, {'$inc' => {"views" => 1}}) Monday, 27 September 2010
- 14. query operators "$ne" "$inc" "$in" "$set" "$nin" "$push" "$mod" "$pushAll" "$all" "$pop" "$size" "$pull" "$exists" "$pullAll" Monday, 27 September 2010
- 15. 3 Map reduce for aggregation Monday, 27 September 2010
- 16. map reduce def self.target_for_report(report) collections = DB['targets'].group(['metric'], { :report_type => report.report_type, :project_name => report.project }, { 'docs' => [] }, "function(doc, prev) { prev.docs.push(doc); }"); end Monday, 27 September 2010
- 17. 4 Indexes are indexes Monday, 27 September 2010
- 18. indexes @blogposts.create_index([[ "comments.by" , Mongo::ASCENDING ]]); db.blogposts.ensureIndex( { "comments.by" : 1 } ); @blogposts.create_index([[ :languages , Mongo::ASCENDING ]]); @blogposts.create_index([[ :time , Mongo::DESCENDING ]]); @blogposts.create_index([[ :author , Mongo::ASCENDING, true ]]); @blogposts.create_index( [[ "comments.vote" , 1,], [ "comments.date", -1 ]]); Monday, 27 September 2010
- 19. 5 GridFS Monday, 27 September 2010
- 20. api grid = Mongo::Grid.new(DB) my_avatar = File.open('toni.jpg','r') id = grid.put(my_avatar) files collection for metadata chunks collection for data Monday, 27 September 2010
- 21. 6 Replication Monday, 27 September 2010
- 22. m/s vs replica set asynchronous replication of data between servers for failover and redundancy only one server (in the set/shard) is active for writes (the primary, or master) at a given time. Monday, 27 September 2010
- 23. replica sets (1.6+) • Supports 1-7 servers in the cluster • Automatic failover • Automatic recovery Monday, 27 September 2010
- 24. 7 Auto-shard Monday, 27 September 2010
- 25. mongo shards Sharding occurs on a per-collection basis Monday, 27 September 2010
- 26. 8 Pro & Cons Monday, 27 September 2010
- 27. pro & cons • schema free > no migrations needed • no sql • update existing data • stable • very nice api Monday, 27 September 2010
- 28. good for • the web • real time • logging • analytics • humans Monday, 27 September 2010
- 29. 9 Links Monday, 27 September 2010
- 30. links • http://api.mongodb.org/ruby/1.0.9/ index.html • http://www.mongodb.org/ • http://mongoid.org/ Monday, 27 September 2010
- 31. 10 Questions Monday, 27 September 2010