3 ms·
How do the underlying queries look for symmetric aggregates? Sadly SQL never supported the ability to compute an aggregate based on the unique values of another
by infinite8s 8y ago
How do the underlying queries look for symmetric aggregates? Sadly SQL never supported the ability to compute an aggregate based on the unique values of another column.
- akalitenya 8y agoMprove does it the way the Looker did it before: CREATE TEMPORARY FUNCTION mprove_array_sum(ar ARRAY<STRING>) AS ((SELECT SUM(CAST(REGEXP_EXTRACT(val, '\\|\\|(\\-?\\d+(?:.\\d+)?)$') AS FLOAT64)) FROM UNNEST(ar) as val)); ... SELECT COALESCE(mprove_array_sum(ARRAY_AGG(DISTINCT CONCAT(CONCAT(CAST(a.id AS STRING), '||'), CAST(a.population AS STRING)))), 0) as a_cohort_size Recently, Looker began to do it differently, most likely to improve bigquery performance: COALESCE(ROUND(COALESCE(CAST( ( SUM(DISTINCT (CAST(ROUND(COALESCE(lesson_5_cohorts.population ,0)*(1/1000*1.0), 9) AS NUMERIC) + (cast(cast(concat('0x', substr(to_hex(md5(CAST(lesson_5_cohorts.id AS STRING))), 1, 15)) as int64) as numeric) * 4294967296 + cast(cast(concat('0x', substr(to_hex(md5(CAST(lesson_5_cohorts.id AS STRING))), 16, 8)) as int64) as numeric)) * 0.000000001 )) - SUM(DISTINCT (cast(cast(concat('0x', substr(to_hex(md5(CAST(lesson_5_cohorts.id AS STRING))), 1, 15)) as int64) as numeric) * 4294967296 + cast(cast(concat('0x', substr(to_hex(md5(CAST(lesson_5_cohorts.id AS STRING))), 16, 8)) as int64) as numeric)) * 0.000000001) ) / (1/1000*1.0) AS FLOAT64), 0), 6), 0) AS lesson_5_cohorts_m_sum_distinct