Why did you choose NUMERIC(18,2) for amount? What alternatives exist and what are the issues with DOUBLE PRECISION?

The NUMERIC(18,2) type is chosen to store the amount, ensuring precise storage of monetary values with two decimal places and avoiding rounding errors.

Alternatives:

• DOUBLE PRECISION — a floating-point type that can lead to inaccuracies due to the way numbers are represented in binary.
• INTEGER with scaling (e.g., storing the amount in cents as an integer) — suitable, but requires additional processing when displaying.

The problem with DOUBLE PRECISION is that operations with it can produce small inaccuracies, which is critical for financial data where accuracy to the cent matters. NUMERIC stores numbers in a decimal format with fixed precision, guaranteeing the correctness of calculations.