error()

error(sketch UddSketch) RETURNS DOUBLE PRECISION

This returns the maximum relative error that a percentile estimate will have (relative to the correct value). This means the actual value will fall in the range defined by approx_percentile(sketch) +/- approx_percentile(sketch)*error(sketch).

This function can only be used on estimators produced by percentile_agg() or uddsketch() calls.

Required arguments

Returns

Sample usage

SELECT error(percentile_agg(data))
FROM generate_series(0, 100) data;

error
-------
 0.001