JSONB and Arrays

Part of the PostgreSQL course

Some data refuses to sit still in columns. A products table where laptops have a RAM size, keyboards have a switch type and monitors have a diagonal, and next month somebody adds candles. You can add a column per attribute and watch the table grow ninety mostly-null columns, or you can invent a key-value side table and hand-roll a query language for it.

The same problem shows up smaller with lists. A post has tags. Three of them, usually. A whole join table for that is often more machinery than the problem deserves, and Postgres will happily let a column hold an array. ...