``` SELECT count(distinct products_id) FROM a_table as a WHERE 1=1 AND products_id in ( SELECT products_id from b_table ); ``` Because hash table construction errors may lead to unstable results
``` SELECT count(distinct products_id) FROM a_table as a WHERE 1=1 AND products_id in ( SELECT products_id from b_table ); ``` Because hash table construction errors may lead to unstable results