Aggregation functions

sum

sum(value) - adds values.

Arguments

• value is any numeric value.

Description

sum(value) adds values ignoring missing data (e.g null values).

Return value

Return value type is the same as the type of the argument.

Examples

Sum all quantities in the transactions table

SELECT sum(quantity) FROM transactions;

sum
100

Sum all quantities in the transactions table, aggregated by item

SELECT item, sum(quantity) FROM transactions;

item	count
apple	53
orange	47

Overflow

sum does not perform overflow check. To avoid overflow, you can cast the argument to wider type.

Cast as long to avoid overflow

SELECT sum(cast(a AS LONG)) FROM table;

ksum

ksum(value) - adds values using Kahan algorithm.

Arguments

• value is any numeric value.

Description

ksum(value) adds values ignoring missing data (e.g null values). Values are added using the

Kahan compensated sum algorithm. This is only beneficial for floating-point values such as float or double.

Return value

Return value type is the same as the type of the argument.

Examples

SELECT ksum(a)

FROM (SELECT rnd_double() a FROM long_sequence(100));

ksum
52.79143968514029

nsum

nsum(value) - adds values using Neumaier algorithm.

Arguments

• value is any numeric value.

Description

nsum(value) adds values ignoring missing data (e.g null values). Values are added using the

Neumaier sum algorithm. This is only beneficial for floating-point values such as float or double.

Return value

Return value type is the same as the type of the argument.

Examples

SELECT nsum(a)

FROM (SELECT rnd_double() a FROM long_sequence(100));

nsum
49.5442334742831

count

count() or count(*) - counts rows.

Arguments

• count does not require arguments.

Description

count() counts rows, irrespective of underlying data.

Return value

Return value type is long.

Examples

• Count of rows in the transactions table.

SELECT count() FROM transactions;

count
100

• Count of rows in the transactions table aggregated by payment_type value.

SELECT payment_type, count() FROM transactions;

cash_or_card	count
cash	25
card	70
null	5

note

null values are aggregated with count().

avg

avg(value) calculates simple average of values

Arguments

• value is any numeric value.

Description

avg(value) averages values ignoring missing data (e.g null values).

Return value

Return value type is double.

Examples

Average transaction amount

SELECT avg(amount) FROM transactions;

avg
22.4

Average transaction amount by payment_type

SELECT payment_type, avg(amount) FROM transactions;

cash_or_card	avg
cash	22.1
card	27.4
null	18.02

min

min(value) - finds the lowest value.

Arguments

• value is any numeric value

Description

min(value) finds the lowest value ignoring missing data (e.g null values).

Return value

Return value type is the same as the type of the argument.

Examples

Lowest transaction amount

SELECT min(amount) FROM transactions;

min
12.5

Lowest transaction amount, by payment_type

SELECT payment_type, min(amount) FROM transactions;

cash_or_card	min
cash	12.5
card	15.3
null	22.2

max

max(value) - finds the highest value.

Arguments

• value is any numeric value

Description

max(value) finds the highest value ignoring missing data (e.g null values).

Return value

Return value type is the same as the type of the argument.

Examples

Highest transaction amount

SELECT max(amount) FROM transactions;

min
55.3

Highest transaction amount by payment_type

SELECT payment_type, max(amount) FROM transactions;

cash_or_card	amount
cash	31.5
card	55.3
null	29.2