hits_100m_single 30000000000 30000000000 key SearchEngineID RegionID ClientIP SearchPhrase func sum uniq uniqExact uniqHLL12 uniqCombined(12) uniqCombined(13) uniqCombined(14) uniqCombined(15) uniqCombined(16) uniqCombined(17) uniqCombined(18) uniqUpTo(3) uniqUpTo(5) uniqUpTo(10) uniqUpTo(25) uniqUpTo(100) uniqTheta SELECT {key} AS k, {func}(UserID) FROM (SELECT {key}, UserID FROM hits_100m_single LIMIT 20000000) GROUP BY k