mongodb: why it should (not) replace your sql database?
DESCRIPTION
Can MongoDB replace SQL, one of the most popular database model in the world? Are we going to not use relational data models in future? The aim of the presentation is to present basic information about the noSQL and MongoDB. It tries to answer this questions by showing interesting possibilites of this noSQL database.TRANSCRIPT
Maciej Miara, April 2014
• Non-relational database model
• Easy horizontal scalability
• Different data structures:
- key-value store
- key-value cache
- object database
- document store
- graph store
- wide-column store
• Denormalization
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Data structure
Data structure
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Object ID
ObjectId("507f191e810c19729de860ea")
Seconds since
the Unix epoch
Machine
identifier
Process idCounter, starts with
random value
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Schema
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Schema
Schema
Second query confirms, that mongo returns null,
when attribute is not found in document
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Querying embedded data
Querying embedded data
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•db.createCollection("log", { capped : true, size : 5242880, max : 5000 } )
• Good for logs or temporary data
Capped collections
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Map-Reduce
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Indexes
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Geospatial indexes
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Geospatial queries
Geospatial queries - examples
Source:
http://docs.mongodb.org
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Full text search
Full text search
Supported languages:
danish, dutch, english, finnish, french, german,
hungarian, italian, norwegian, portuguese, norwegian,
rommanian, russian, spanish, swedish, turkish
Source:
http://docs.mongodb.org
Sharding
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Sharding
Source:
http://docs.mongodb.org
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GridFS
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Javascript driven
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ACID
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Transaction system
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Journaling
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Write concern
Unacknowledged
Source:
http://docs.mongodb.org
Acknowledged
Source:
http://docs.mongodb.org
Journal acknowledged
Source:
http://docs.mongodb.org
Replica acknowledged
Source:
http://docs.mongodb.org
Some people complain
about Mongo, but…
…they just don’t know,
why they chose it
• „My friend from studies used it”
• „I was just curious”
• „Recommended by other company
(in their project it worked well)”
• „Technical (!) client wanted it”
• „After all-night long party I decided
to use it”
• „I heard that
Microsoft/Google/NYT/(fill in any
corpo you want) uses it”
Do NOT use Mongo, if you:
• like joins
• Need really transactional system
• Have relational data
• Want full ACID without any
compromises
