[ https://issues.apache.org/jira/browse/PHOENIX-4618?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
chenglei resolved PHOENIX-4618. ------------------------------- Resolution: Fixed Fix Version/s: 4.15.0 > Optimize out order-by on sort-merge-join when possible > ------------------------------------------------------ > > Key: PHOENIX-4618 > URL: https://issues.apache.org/jira/browse/PHOENIX-4618 > Project: Phoenix > Issue Type: Improvement > Reporter: Maryann Xue > Assignee: Maryann Xue > Priority: Major > Fix For: 4.15.0 > > > To do this, \{{OrderPreservingTracker}} relies solely on primary keys for > inferring alignment between order-by expressions and the input sortedness. To > implement this improvement, we need to have extra information of sortedness > which supports equivalent sorted expressions. For example, > {code}SELECT * FROM T1 JOIN T2 ON T1.a = T2.a and T1.b = T2.b{code} > The result of the sort-merge-join is sorted on (T1.a, T1.b) and (T2.a, T2.b) > at the same time. > Thus, both 1) > {code}SELECT * FROM T1 JOIN T2 ON T1.a = T2.a and T1.b = T2.b ORDER BY T1.a, > T1.b{code} > and 2) > {code}SELECT * FROM T1 JOIN T2 ON T1.a = T2.a and T1.b = T2.b ORDER BY T2.a, > T2.b{code} > should avoid doing an extra order-by after the sort-merge-join operation. -- This message was sent by Atlassian JIRA (v7.6.3#76005)