1. MongoDB Advanced Topics
César D. Rodas
crodas@php.net
http://crodas.org/
Yahoo! Open Hack Day 2010
São Paulo, Brasil
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2. Who is this fellow?
Paraguayan
Zealot of
• Open Source
• PHP
• MongoDB
PECL Developer
... and few other things
@crodas - http://crodas.org/ - L EX
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3. I'd like to thanks to...
10gen
Yahoo!
My Brazilian friends
@crodas - http://crodas.org/ - L EX
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4. Agenda
Introduction to MongoDB
MongoDB Queries
Real life example:
• Designing data model for a Wordpress.com like site
• Optimize our data model to run in sharded environment
@crodas - http://crodas.org/ - L EX
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5. MongoDB
<EN>Mongo</EN> != <PT>Mongo</PT>
Document oriented database
Fast, Scalable, Easy to use
Support Indexes
• Simple
• Compound
• Geo spatial
Support sharding
PECL client
@crodas - http://crodas.org/ - L EX
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6. Documents?
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7. It's just an Array()
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8. In fact everything is an
Array() in MongoDB
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9. http://bit.ly/mongodb-php
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10. The fun part
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11. MongoDB - Operations
Select
• $gt, $lt, $gte, $lte, $eq, $neq: >, <, >=, <=, ==, !=
• $in, $nin
• $size, $exists
• $where: Any javascript expression
• group()
• limit()
• skip()
Update
• $set
• $unset
• $push
• $pull
• $inc
@crodas - http://crodas.org/ - L EX
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12. pecl install mongo
@crodas - http://crodas.org/ - L EX
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13. MongoDB - Connection
/* connects to localhost:27017 */
$connection = new Mongo();
/* connect to a remote host (default port) */
$connection = new Mongo( "example.com" );
/* connect to a remote host at a given port */
$connection = new Mongo( "example.com:65432" );
/* select some DB (and create if it doesn't exits yet) */
$db = $connection->selectDB("db name");
/* select a "table" (collection) */
$table = $db->getCollection("table");
@crodas - http://crodas.org/ - L EX
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14. FROM SQL to MongoDB
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15. MongoDB - Count
/* SELECT count(*) FROM table */
$collection->count();
/* SELECT count(*) FROM table WHERE foo = 1 */
$collection->find(array("foo" => 1))->count();
@crodas - http://crodas.org/ - L EX
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16. MongoDB - Queries
/*
* SELECT * FROM table WHERE field IN (5,6,7) and enable=1
* and worth < 5
* ORDER BY timestamp DESC
*/
$collection->ensureIndex(
array('field'=>1, 'enable'=>1, 'worth'=>1, 'timestamp'=>-1)
);
$filter = array(
'field' => array('$in' => array(5,6,7)),
'enable' => 1,
'worth' => array('$lt' => 5)
);
$results = $collection->find($filter)->sort(array('timestamp' => -1));
@crodas - http://crodas.org/ - L EX
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17. MongoDB - Pagination
/*
* SELECT * FROM table WHERE field IN (5,6,7) and enable=1
* and worth < 5
* ORDER BY timestamp DESC LIMIT $offset, 20
*/
$filter = array(
'field' => array('$in' => array(5,6,7)),
'enable' => 1,
'worth' => array('$lt' => 5)
);
$cursor = $collection->find($filter);
$cursor->sort(array('timestamp' => -1))->skip($offset)->limit(20);
foreach ($cursor as $result) {
var dump($result);
}
@crodas - http://crodas.org/ - L EX
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18. Designing data structure
Simple multi-blog system
@crodas - http://crodas.org/ - L EX
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19. MongoDB - Collections
Blog
Post
User
Comment
@crodas - http://crodas.org/ - L EX
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20. Blog document
$blog = array(
"user" => <userref>,
"title" => "Foo bar blog"
"url" => array(
"foobar.foobar.com",
"anotherfoo.foobar.com",
),
"permissions" => array(
"edit" => array(<userref>, <userref>)
);
"post" => 1,
...
);
@crodas - http://crodas.org/ - L EX
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21. Post document
$post = array(
"blog" => <blogref>,
"author" => <userref>,
"uri" => "/another-post",
"title" => "Another post",
"excerpt" => "bla, bla, bla",
"body" => "bar, foo bar, foo, bar",
"tags" => array("list", "of tags"),
"published" => true,
"date" => <mongodate>,
);
@crodas - http://crodas.org/ - L EX
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22. Missing docs.
$comment = array(
"post" => <postref>,
"name" => "foobar",
"email" => "foo@bar.com",
"comment" => "Hello world",
"date" => <mongodate>,
);
$user = array(
"user" => "crodas",
"email" => "crodas@php.net",
"password" => "a1bad96dc68f891ca887d50eb3fb65ec82123d05",
"name" => "Cesar Rodas",
);
@crodas - http://crodas.org/ - L EX
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23. About indexes
$blog col->ensureIndex(array("url" => 1));
$post col->ensureIndex(array("blog" => 1, "date" => -1));
$post col->ensureIndex(array("blog" => 1, "uri" => 1), array("unique" => 1));
$comment col->ensureIndex(array("post" => 1, "date" => -1));
$user col->ensureIndex(array("user" => 1), array("unique" => 1));
$user col->ensureIndex(array("email" => 1), array("unique" => 1));
@crodas - http://crodas.org/ - L EX
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24. That's it.
@crodas - http://crodas.org/ - L EX
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25. Hum...
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26. Until now, nothing new
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27. Let's shard it!
@crodas - http://crodas.org/ - L EX
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28. Strategy
Shard Blog collection
Shard User collection
Other collections are isolated
• Create namespaces for post and comments (foo.post, foo.comments)
• Modify Blog collection, add info about "namespace" (and DB).
MongoDB will distribute our DB and namespaces
@crodas - http://crodas.org/ - L EX
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29. Configuring the sharding
/* Assuming you have already MongoDB running
* on a sharded env., you should do this once.
*
* $admin is a connection to the "admin" DB.
*/
$admin->command(array(
"shardcollection" => "blog",
"key" => array("uri" => 1),
));
$admin->command(array(
"shardcollection" => "user",
"key" => array("user" => 1),
"unique" => true,
));
@crodas - http://crodas.org/ - L EX
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30. New blog document
$blog = array(
"user" => <userref>,
"title" => "Foo bar blog"
"url" => array(
"foobar.foobar.com",
"anotherfoo.foobar.com",
),
"permissions" => array(
"edit" => array(<userref>, <userref>)
);
"post" => 1,
"namespace" => "3h3g3k3",
"database" => "34fs321",
);
@crodas - http://crodas.org/ - L EX
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31. Select the DB and namespace
to use "post" and "comments"
@crodas - http://crodas.org/ - L EX
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32. Questions?
@crodas - http://crodas.org/ - L EX
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33. Thank you hackers!
@crodas - http://crodas.org/ - L EX
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34. MongoDB is looking from
Brazilian help.
@crodas - http://crodas.org/ - L EX
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35. @crodas
crodas.org
@crodas - http://crodas.org/ - L EX
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