M102: MongoDB for DBAs

README.md

https://university.mongodb.com/courses/M102/about

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• Concepts
  • support for new hardware
    • parallelism
    • clustering
    • scaling
  • easier development
  • complex data (unstructured & polymorphic)

Scaling

• horizontal (vs vertical)
  • subsystem failures are common
  • complex communication within system
• scaling vs rich features
  • we need to trade some features for scalability & speed (CAP)
    • distributed joins
    • complex distributed transactions

Documents

• lack of joins impiles need for different (non-relational) data model
  • documents = "some structure" (vs. key-value sotrage)

BSON

• Goals
  • fast scanability
  • datatypes
    • Date
    • BinData
    • int/long (32/64 bit)

Compact representation (sometimes) as a bonus.
Types matter when quering data: .find({price:1.25}) vs .find({price:"1.25"})

Dynamic Schema

• Advantages of dynamic schema
  • polymorphic data (e.g. circles and rectangles in figure collection)
  • agile/iterative development
    • db migrations are sometimes easier

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https://docs.mongodb.org/manual/reference/operator/query/
https://docs.mongodb.org/manual/reference/operator/update/ update({...}, {..}, {multi: false})