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Categories: Aggregate, Window

VAR_POP

Returns the population variance of non-NULL records.

Syntax​

VAR_POP(col_name NUMERIC) → NUMERIC​

  • col_name: The name of the column for which to return the population variance. The values in the column must be numbers, such as INT, DOUBLE, or FLOAT.

Examples

VAR_POP example 
SELECT VAR_POP(pop) FROM Samples."samples.dremio.com"."zips.json";
-- 1.5167869917122573E8
VAR_POP example 
SELECT VAR_POP(fare_amount) FROM Samples."samples.dremio.com"."NYC-taxi-trips";
-- 181.2618702273222
VAR_POP example: Window function with cumulative window frame 
SELECT city, state, pop, VAR_POP(pop)
  OVER (PARTITION BY state ORDER BY city RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
FROM Samples."samples.dremio.com"."zips.json";
-- city, state, pop, EXPR$3
-- 98791, AK, 5345, 3.183470165355581E7
-- AKHIOK, AK, 13309, 3.1964736864852075E7
-- AKIACHAK, AK, 481, 3.1556568197284516E7
-- ...
VAR_POP example: Window function with sliding window frame 
SELECT city, state, pop, VAR_POP(pop)
  OVER (PARTITION BY state ORDER BY city ROWS BETWEEN 1 PRECEDING AND 2 FOLLOWING)
FROM Samples."samples.dremio.com"."zips.json";
-- city, state, pop, EXPR$3
-- 98791, AK, 5345, 2.796015288888889E7
-- AKHIOK, AK, 13309, 2.7931748E7
-- AKIACHAK, AK, 481, 3.1007691E7
-- ...

Usage Notes​

For single record inputs, VAR_POP returns 0.

The VAR_POP function supports optional PARTITION BY, ORDER_BY, and cumulative and sliding window frame subclauses. See Window Functions for more information and syntax.