Days 22-24: SQL & Databases

Ideas:

• Primary keys, foreign keys, uniqueness of data
  • PRIMARY KEY
  • FOREIGN KEY
  • UNIQUE
• Aggregations
  • COUNT
  • SUM
  • GROUP BY
  • ORDER BY
• Performance & Indexes
  • CREATE INDEX
  • EXPLAIN
  • “BIG” data
    • Redshift (AWS), BigQuery (Google Cloud)
    • Presto, SparkSQL
    • ElasticSearch

Outcomes of this studying

You should:

• be able to explain what a PRIMARY KEY is and why it’s important to use them
• be able to describe how databases are used differently at company’s with “big” data