Mathematical Functions & Operators#

1. Mathematical Operators#

Operator

Description

Example(s)

numeric_type + numeric_type → numeric_type

Addition

2 + 3 → 5

+ numeric_type → numeric_type

Unary plus (no operation)

+ 3.5 → 3.5

numeric_type - numeric_type → numeric_type

Subtraction

2 - 3 → -1

- numeric_type → numeric_type

Negation

- (-4) → 4

numeric_type * numeric_type → numeric_type

Multiplication

2 * 3 → 6

numeric_type / numeric_type → numeric_type

Division (for integral types, division truncates the result towards zero)

5.0 / 2 → 2.5000000000000000
5 / 2 → 2
(-5) / 2 → -2

numeric_type % numeric_type → numeric_type

Modulo (remainder); available for smallint, integer, bigint, and numeric

5 % 4 → 1

numeric ^ numeric → numeric
double precision ^ double precision → double precision

Exponentiation
Unlike typical mathematical practice, multiple uses of ^ will associate left to right by default:

2 ^ 3 → 8
2 ^ 3 ^ 3 → 512
2 ^ (3 ^ 3) → 134217728

|/ double precision → double precision

Square root

|/ 25.0 → 5

||/ double precision → double precision

Cube root

||/ 64.0 → 4

@ numeric_type → numeric_type

Absolute value

@ -5.0 → 5

integral_type & integral_type → integral_type

Bitwise AND

91 & 15 → 11

integral_type | integral_type → integral_type

Bitwise OR

32 | 3 → 35

integral_type # integral_type → integral_type

Bitwise exclusive OR

17 # 5 → 20

~ integral_type → integral_type

Bitwise NOT

~1 → -2

integral_type << integer → integral_type

Bitwise shift left

1 << 4 → 16

integral_type >> integer → integral_type

Bitwise shift right

8 >> 2 → 2

Where numeric_type includes integral_types, numeric, real and double precision; and integral_type includes smallint, integer and bigint.

2. Mathematical Functions#

Function

Description

Example(s)

abs ( numeric_type ) → numeric_type

Absolute value

abs(-17.4) → 17.4

cbrt ( double precision ) → double

precision Cube root

cbrt(64.0) → 4

ceil ( numeric ) → numeric
ceil ( double precision ) → double precision

Nearest integer greater than or equal to argument

ceil(42.2) → 43
ceil(-42.8) → -42

ceiling ( numeric ) → numeric
ceiling ( double precision ) → double precision

Nearest integer greater than or equal to argument (same as ceil)

ceiling(95.3) → 96

degrees ( double precision ) → double precision

Converts radians to degrees

degrees(0.5) → 28.64788975654116

div ( y numeric, x numeric ) → numeric

Integer quotient of y/x (truncates towards zero)

div(9, 4) → 2

exp ( numeric ) → numeric
exp ( double precision ) → double precision

Exponential (e raised to the given power)

exp(1.0) → 2.7182818284590452

factorial ( bigint ) → numeric

Factorial

factorial(5) → 120

floor ( numeric ) → numeric
floor ( double precision ) → double precision

Nearest integer less than or equal to argument

floor(42.8) → 42
floor(-42.8) → -43

gcd ( numeric_type, numeric_type ) → numeric_type

Greatest common divisor (the largest positive number that divides both inputs with no remainder); returns 0 if both inputs are zero; available for integer, bigint, and numeric

gcd(1071, 462) → 21

lcm ( numeric_type, numeric_type ) → numeric_type

Least common multiple (the smallest strictly positive number that is an integral multiple of both inputs); returns 0 if either input is zero; available for integer, bigint, and numeric

lcm(1071, 462) → 23562

ln ( numeric ) → numeric
ln ( double precision ) → double precision

Natural logarithm

ln(2.0) → 0.6931471805599453

log ( numeric ) → numeric
log ( double precision ) → double precision

Base 10 logarithm

log(100) → 2

log10 ( numeric ) → numeric
log10 ( double precision ) → double precision

Base 10 logarithm (same as log)

log10(1000) → 3

log ( b numeric, x numeric ) → numeric

Logarithm of x to base b

log(2.0, 64.0) → 6.0000000000

min_scale ( numeric ) → integer

Minimum scale (number of fractional decimal digits) needed to represent the supplied value precisely

min_scale(8.4100) → 2

mod ( y numeric_type, x numeric_type ) → numeric_type

Remainder of y/x; available for smallint, integer, bigint, and numeric

mod(9, 4) → 1

pi ( ) → double precision

Approximate value of π

pi() → 3.141592653589793

power ( a numeric, b numeric ) → numeric
power ( a double precision, b double precision ) → double precision

a raised to the power of b

power(9, 3) → 729

radians ( double precision ) → double precision

Converts degrees to radians

radians(45.0) → 0.7853981633974483

round ( numeric ) → numeric
round ( double precision ) → double precision

Rounds to nearest integer. For numeric, ties are broken by rounding away from zero. For double precision, the tie-breaking behavior is platform dependent, but “round to nearest even” is the most common rule.

round(42.4) → 42

round ( v numeric, s integer ) → numeric

Rounds v to s decimal places. Ties are broken by rounding away from zero.

round(42.4382, 2) → 42.44

scale ( numeric ) → integer

Scale of the argument (the number of decimal digits in the fractional part)

scale(8.4100) → 4

sign ( numeric ) → numeric
sign ( double precision ) → double precision `

Sign of the argument (-1, 0, or +1)

sign(-8.4) → -1

sqrt ( numeric ) → numeric
sqrt ( double precision ) → double precision

Square root

sqrt(2) → 1.4142135623730951

trim_scale ( numeric ) → numeric

Reduces the value’s scale (number of fractional decimal digits) by removing trailing zeroes

trim_scale(8.4100) → 8.41

trunc ( numeric ) → numeric
trunc ( double precision ) → double precision

Truncates to integer (towards zero)

trunc(42.8) → 42
trunc(-42.8) → -42

trunc ( v numeric, s integer ) → numeric

Truncates v to s decimal places

trunc(42.4382, 2) → 42.43

width_bucket ( operand numeric, low numeric, high numeric, count integer ) → integer
width_bucket ( operand double precision, low double precision, high double precision, count integer ) → integer

Returns the number of the bucket in which operand falls in a histogram having count equal-width buckets spanning the range low to high. Returns 0 or count+1 for an input outside that range.

width_bucket(5.35, 0.024, 10.06, 5) → 3

width_bucket ( operand anycompatible, thresholds anycompatiblearray ) → integer

Returns the number of the bucket in which operand falls given an array listing the lower bounds of the buckets. Returns 0 for an input less than the first lower bound. operand and the array elements can be of any type having standard comparison operators. The thresholds array must be sorted, smallest first, or unexpected results will be obtained.

width_bucket(now(), array[‘yesterday’, ‘today’, ‘tomorrow’]::timestamptz[]) → 2

Functions working with double precision data are mostly implemented on top of the host system’s C library, so accuracy and behavior in boundary cases can vary depending on the host system.

3. Random Functions#

Function

Description

Example(s)

random ( ) → double precision

Returns a random value in the range 0.0 <= x < 1.0

random() → 0.897124072839091

setseed ( double precision ) → void

Sets the seed for subsequent random() calls; argument must be between -1.0 and 1.0, inclusive

setseed(0.12345)

4. Trigonometric Functions#

Function

Description

Example(s)

acos ( double precision ) → double precision

Inverse cosine, result in radians

acos(1) → 0

acosd ( double precision ) → double precision

Inverse cosine, result in degrees

acosd(0.5) → 60

asin ( double precision ) → double precision

Inverse sine, result in radians

asin(1) → 1.5707963267948966

asind ( double precision ) → double precision

Inverse sine, result in degrees

asind(0.5) → 30

atan ( double precision ) → double precision

Inverse tangent, result in radians

atan(1) → 0.7853981633974483

atand ( double precision ) → double precision

Inverse tangent, result in degrees

atand(1) → 45

atan2 ( y double precision, x double precision ) → double precision

Inverse tangent of y/x, result in radians

atan2(1, 0) → 1.5707963267948966

atan2d ( y double precision, x double precision ) → double precision

Inverse tangent of y/x, result in degrees

atan2d(1, 0) → 90

cos ( double precision ) → double precision

Cosine, argument in radians

cos(0) → 1

cosd ( double precision ) → double precision

Cosine, argument in degrees

cosd(60) → 0.5

cot ( double precision ) → double precision

Cotangent, argument in radians

cot(0.5) → 1.830487721712452

cotd ( double precision ) → double precision

Cotangent, argument in degrees

cotd(45) → 1

sin ( double precision ) → double precision

Sine, argument in radians

sin(1) → 0.8414709848078965

sind ( double precision ) → double precision

Sine, argument in degrees

sind(30) → 0.5

tan ( double precision ) → double precision

Tangent, argument in radians

tan(1) → 1.5574077246549023

tand ( double precision ) → double precision

Tangent, argument in degrees

tand(45) → 1

5. Hyperbolic Functions#

Function

Description

Example(s)

sinh ( double precision ) → double precision

Hyperbolic sine

sinh(1) → 1.1752011936438014

cosh ( double precision ) → double precision

Hyperbolic cosine

cosh(0) → 1

tanh ( double precision ) → double precision

Hyperbolic tangent

tanh(1) → 0.7615941559557649

asinh ( double precision ) → double precision

Inverse hyperbolic sine

asinh(1) → 0.881373587019543

acosh ( double precision ) → double precision

Inverse hyperbolic cosine

acosh(1) → 0

atanh ( double precision ) → double precision

Inverse hyperbolic tangent

atanh(0.5) → 0.5493061443340548