Appendix: Database Vocabulary

There are a few words that anyone wanting to understand databases should know.

  1. Postgres vs. PostgreSQL: These are interchangeable and both refer to the popular relational database server.

  2. Predicate: This is an attribute of a node in a graph database or a filter in SQL’s WHERE clause.

  3. Tuple: A tuple is a finite ordered list of elements. It’s a data type in programming languages such as Elixir, and it’s interchangeable with a row in a relational database. For example, a tuple with 2 elements is a “double”, 3 elements is a “triple”, 4 elements is a “quadruple”, etc. They all basically end in “uple”.