Gopal V created HIVE-20333: ------------------------------ Summary: CBO: Join removal based on PK-FK declared constraints Key: HIVE-20333 URL: https://issues.apache.org/jira/browse/HIVE-20333 Project: Hive Issue Type: Bug Reporter: Gopal V
A query of the following shape can have its customer join removed entirely on the basis of the key containment between customer & store_sales. {code} select c_customer_sk,sum(ss_quantity*ss_sales_price) ssales from store_sales ,customer where ss_customer_sk = c_customer_sk group by c_customer_sk; {code} This query after join removal can be encoded in as {code} select ss_customer_sk as c_customer_sk,sum(ss_quantity*ss_sales_price) ssales from store_sales where ss_customer_sk is not null group by ss_customer_sk; {code} The rewrite is not applied today and the current PK-FK relationship does not allow for a nullable relationship (i.e a declared Foreign Key can't be NULL). -- This message was sent by Atlassian JIRA (v7.6.3#76005)