Language reference
PERCENTILE_DISC (discrete percentile)
Syntax
PERCENTILE_DISC(<fraction>) WITHIN GROUP (ORDER BY <expr>)
PERCENTILE_DISC(<fraction>, <expr>)
γ customer_id, PERCENTILE_DISC(0.5, order_date) → halfway (Orders)Description
PERCENTILE_DISC is the first actual value of a group that a given fraction of its values reaches, so it is always one of the values, and works on dates and strings as well as numbers.
Technical Description
The value at position ⌈p × n⌉ − 1, at least 0, among the n non-NULL values in ascending order; NULL for none. The fraction must be between 0 and 1 and the same in every row; the order is ascending only. See PERCENTILE_CONT for both percentiles and a worked example.
Examples
γ customer_id, PERCENTILE_DISC(0.5, order_date) → halfway (Orders)GROUP customer_id, PERCENTILE_DISC(0.5, order_date) -> halfway (Orders)