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ASF GitHub Bot commented on DRILL-4707: --------------------------------------- Github user jinfengni commented on the issue: https://github.com/apache/drill/pull/515 I cherry-picked CALCITE-528 from Calcite master branch, and put it into Drill forked version. @amansinha100 , could you please review this PR? thanks! > Conflicting columns names under case-insensitive policy lead to either memory > leak or incorrect result > ------------------------------------------------------------------------------------------------------ > > Key: DRILL-4707 > URL: https://issues.apache.org/jira/browse/DRILL-4707 > Project: Apache Drill > Issue Type: Bug > Reporter: Jinfeng Ni > Assignee: Jinfeng Ni > Priority: Critical > > On latest master branch: > {code} > select version, commit_id, commit_message from sys.version; > +-----------------+-------------------------------------------+---------------------------------------------------------------------------------+ > | version | commit_id | > commit_message | > +-----------------+-------------------------------------------+---------------------------------------------------------------------------------+ > | 1.7.0-SNAPSHOT | 3186217e5abe3c6c2c7e504cdb695567ff577e4c | DRILL-4607: > Add a split function that allows to separate string by a delimiter | > +-----------------+-------------------------------------------+---------------------------------------------------------------------------------+ > {code} > If a query has two conflicting column names under case-insensitive policy, > Drill will either hit memory leak, or incorrect issue. > Q1. > {code} > select r_regionkey as XYZ, r_name as xyz FROM cp.`tpch/region.parquet`; > Error: SYSTEM ERROR: IllegalStateException: Memory was leaked by query. > Memory leaked: (131072) > Allocator(op:0:0:1:Project) 1000000/131072/2490368/10000000000 > (res/actual/peak/limit) > Fragment 0:0 > {code} > Q2: return only one column in the result. > {code} > select n_nationkey as XYZ, n_regionkey as xyz FROM cp.`tpch/nation.parquet`; > +------+ > | XYZ | > +------+ > | 0 | > | 1 | > | 1 | > | 1 | > | 4 | > | 0 | > | 3 | > {code} > The cause of the problem seems to be that the Project thinks the two incoming > columns as identical (since Drill adopts case-insensitive for column names in > execution). > The planner should make sure that the conflicting columns are resolved, since > execution is name-based. -- This message was sent by Atlassian JIRA (v6.3.4#6332)