Decimal Operations

The precision (p) and scale (s) of a DECIMAL result depend on the operation used to derive it. The following rules define the precision and scale that result from arithmetic operations on two decimal values having precisions p₁ and p₂ and respective scales s₁ and s₂. Rules are also provided for the resulting precision and scale of aggregate functions that operate on a single expression having a precision of p₁ and a scale of s₁. Arithmetic operations and aggregate functions are discussed further in Chapter 8 “Expressions”

Addition and Subtraction

p = MIN(27, MAX (p₁ - s₁ , p₂ - s₂) + MAX(s₁, s₂)+ 1)

s = MAX (s₁,s₂)

Multiplication

p = MIN (27, p₁ + p₂)

s = MIN (27, s₁ + s₂)

Division

p = 27

s = 27 - MIN (27, p₁ - s₁ + s₂)

where p₁ and s₁ describe the numerator operand, and p₂ and s₂ describe the denominator operand.

MAX and MIN Functions

p = p₁

s = s₁

SUM Function

p = 27

s = s₁

AVG Function

p = 27

s = 27 - p₁ + s₁