Referencing the alias
length_road in the
WHERE clause does not seem to be allowed. Does this query as written cause the
ST_LENGTH operation to be run more than once per record, and if so, how can that be avoided?
SELECT roads_nat.*, ST_LENGTH(roads_nat.road_geom) AS length_road FROM `bigquery-public-data.geo_us_roads.us_national_roads` AS roads_nat WHERE ST_LENGTH(roads_nat.road_geom) > 1000 -- vs. length_road > 1000