From TEIID-3743 you'll also need to account for the nulls in the on clause - v1.c1 = v2.c1 or (v1.c1 is null and v2.c1 is null).

Impala Translator - Support Multiple Count Distinct with Group By ----------------------------------------------------------------- Key: TEIID-4227 URL: https://issues.jboss.org/browse/TEIID-4227 Project: Teiid Issue Type: Feature Request Components: Misc. Connectors Affects Versions: 8.13.3 Reporter: Scott Wallace Assignee: Steven Hawkins This is somewhat related to TEIID-3743, which added support of multiple count distinct metrics. We have a requirement to allow multiple count distinct metrics grouped by common attributes. Currently, we get a failure as follows: {noformat}org.teiid.runtime.client.TeiidClientException: java.lang.RuntimeException: Remote org.teiid.core.TeiidProcessingException: TEIID30504 vw_impression_click_transaction_process_date_detail: 500051 TEIID11008:TEIID11004 Error executing statement(s): [Prepared Values: [] SQL: SELECT g_0.process_date_key, SUM(g_0.num_clicks), SUM(g_0.num_impressions), COUNT(DISTINCT g_0.orderid), COUNT(DISTINCT g_0.`hash_tid`), SUM(g_0.sales) FROM detail.vw_impression_click_transaction_process_date_detail g_0 WHERE g_0.process_date_key >= '2016-05-22' AND g_0.process_date_key < '2016-05-23' AND g_0.advertiser_key = 12345 GROUP BY g_0.process_date_key] {noformat} To allow this request to succeed, we could have translator write that Impala query as: {noformat} select nvl(v1.c1,v2.c1), nvl(v1.c2,v1.c2), nvl(v1.c3,v1.c3), v1.c4, v2.c5, nvl(v1.c6,v1.c6) from ( SELECT g_0.process_date_key as c1, SUM(g_0.num_clicks) as c2, SUM(g_0.num_impressions) as c3, COUNT(DISTINCT g_0.orderid) as c4, SUM(g_0.sales) as c6 FROM detail.vw_impression_click_transaction_process_date_detail g_0 WHERE g_0.process_date_key >= '2016-05-22' AND g_0.process_date_key < '2016-05-23' AND g_0.advertiser_key = 12345 GROUP BY g_0.process_date_key ) v1 inner join ( SELECT g_0.process_date_key as c1, SUM(g_0.num_clicks) as c2, SUM(g_0.num_impressions) as c3, COUNT(DISTINCT g_0.`hash_tid`) as c5, SUM(g_0.sales) as c6 FROM detail.vw_impression_click_transaction_process_date_detail g_0 WHERE g_0.process_date_key >= '2016-05-22' AND g_0.process_date_key < '2016-05-23' AND g_0.advertiser_key = 12345 GROUP BY g_0.process_date_key ) v2 on v1.c1 = v2.c1; {noformat} FYI [~shawkins]