[jira] [Created] (KYLIN-2173) push down limit leads to wrong answer when filter is loosened

["Dayue Gao (JIRA)" <ji...@apache.org>]

Dayue Gao created KYLIN-2173:
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             Summary: push down limit leads to wrong answer when filter is loosened
                 Key: KYLIN-2173
                 URL: https://issues.apache.org/jira/browse/KYLIN-2173
             Project: Kylin
          Issue Type: Bug
          Components: Storage - HBase
    Affects Versions: v1.5.4.1
            Reporter: Dayue Gao
            Assignee: Dayue Gao


To reproduce:
{noformat}
select
 test_kylin_fact.cal_dt
 ,sum(test_kylin_fact.price) as GMV
 FROM test_kylin_fact 
 left JOIN edw.test_cal_dt as test_cal_dt 
 ON test_kylin_fact.cal_dt = test_cal_dt.cal_dt 
 where test_cal_dt.week_beg_dt in ('2012-01-01', '2012-01-20')
 group by test_kylin_fact.cal_dt 
 limit 12
{noformat}

Kylin returns 5 rows, expect 12 rows.

Root cause: filter condition may be loosened when we translate derived filter in DerivedFilterTranslator. If we push down limit, query server won't get enough valid records from storage. In the above example, 24 rows returned from storage, only 5 are valid.




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