Aggregation functions

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

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().

haversine_dist_deg#

haversine_dist_deg(lat, lon, ts) - traveled distance for a series of lat/lon points.

Arguments#

lat is the latitude expressed as degrees in decimal format (double)
lon is the longitude expressed as degrees in decimal format (double)
ts is the timestamp for the data point

Description#

This is an aggregatation function that calculates the traveled distance for a series of lat/lon points.

Return value#

Return value type is double.

Examples#

Calculate the aggregate traveled distance for each car_id

SELECT car_id, haversine_dist_deg(lat, lon, k)
  FROM table rides

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

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

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

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

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

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;