Computing a moving maximum in BigQuery

Question

Given a BigQuery table with some ordering, and some numbers, I\'d like to compute a \"moving maximum\" of the numbers -- similar to a moving average, but for a maximum inste

Answer 1

There's an example creating a moving using window function in the docs here.

Quoting:

The following example calculates a moving average of the values in the current row and the row preceding it. The window frame comprises two rows that move with the current row.

#legacySQL
SELECT
  name,
  value,
  AVG(value)
    OVER (ORDER BY value
          ROWS BETWEEN 1 PRECEDING AND CURRENT ROW)
    AS MovingAverage
FROM
  (SELECT "a" AS name, 0 AS value),
  (SELECT "b" AS name, 1 AS value),
  (SELECT "c" AS name, 2 AS value),
  (SELECT "d" AS name, 3 AS value),
  (SELECT "e" AS name, 4 AS value);