Computed Pattern

Use this pattern if you need to compute similar computations many times.

Math operations
Fan out operations
Roll-up operations

Roll Up Ops

Which one of the following scenarios is best suited for the application of the Computed Pattern?

We need to calculate a value that is displayed 100 times a minute and is based on a field which updates once a minute.

Lab: Apply the Computed Pattern

Result

{
  "_id": ObjectId("5c9414f25e6aff2b8870a2d0"),
  "zone": 13,
  "date": ISODate("2019-03-21T00:00:00.000Z"),
  "kW per day": {
    "consumption": 9756,
    "self-produced": 2059,
    "city-supplemented": 7700
  }
}

Bucket Pattern(used in IoT)

Which one of the following requirements in our system is the best candidate to use the Bucket Pattern?

Schema Versioning Pattern

Avoid downtime while performing schema upgrades.

Tree Patterns

Company Organization Chars
Books Subjects
Categories of a Shop

Model Tree Structures

Parent References
Child References
Array of Ancestors
Materialized Paths

Ancestor Array + Parent Model

Polymorphic Pattern

Single View solution

Which one of the following scenarios is best suited for the use of the Polymorphic Pattern? The organization acquired different companies over the years, serving the same markets with the same customers and there is a requirement to merge all systems into one.

Other Patterns

Approximation Pattern
- avoiding performing an operation too often
Outlier Pattern
- keeping the focus on the most frequent use cases

This can be used for track page views

M320: Chapter 4: Patterns Part 2