Mostafa Mokhtar created IMPALA-7020: ---------------------------------------
Summary: Order by expressions in Analytical functions are not materialized causing severe slow down Key: IMPALA-7020 URL: https://issues.apache.org/jira/browse/IMPALA-7020 Project: IMPALA Issue Type: Bug Components: Frontend Affects Versions: Impala 2.12.0 Reporter: Mostafa Mokhtar Attachments: Slow case profile.txt, Workaround profile.txt Order by expressions in Analytical functions are not materialized and cause queries to run much slower. The rewrite for the query below is 20x faster, profiles attached. Repro {code} select * FROM ( SELECT o.*, ROW_NUMBER() OVER(ORDER BY evt_ts DESC) AS rn FROM ( SELECT l_orderkey,l_partkey,l_linenumber,l_quantity, cast (l_shipdate as string) evt_ts FROM lineitem WHERE l_shipdate BETWEEN '1992-01-01 00:00:00' AND '1992-01-15 00:00:00' ) o ) r WHERE rn BETWEEN 1 AND 101 ORDER BY rn; {code} Workaround {code} select * FROM ( SELECT o.*, ROW_NUMBER() OVER(ORDER BY evt_ts DESC) AS rn FROM ( SELECT l_orderkey,l_partkey,l_linenumber,l_quantity, cast (l_shipdate as string) evt_ts FROM lineitem WHERE l_shipdate BETWEEN '1992-01-01 00:00:00' AND '1992-01-15 00:00:00' union all SELECT l_orderkey,l_partkey,l_linenumber,l_quantity, cast (l_shipdate as string) evt_ts FROM lineitem limit 0 ) o ) r WHERE rn BETWEEN 1 AND 101 ORDER BY rn; {code} -- This message was sent by Atlassian JIRA (v7.6.3#76005)