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Ashutosh Chauhan commented on HIVE-16102: ----------------------------------------- checkForNoAggr() is explicitly checking for empty grouping set. Not sure when it was added if there was a good reason for it. Can't think of any at the moment. But before removing that lets add a test case for it. Also there is HIVE_GROUPING_SETS_EXPR_NOT_IN_GROUPBY(10213) Can that be removed too? > Grouping sets do not conform to SQL standard > -------------------------------------------- > > Key: HIVE-16102 > URL: https://issues.apache.org/jira/browse/HIVE-16102 > Project: Hive > Issue Type: Bug > Components: Operators, Parser > Affects Versions: 1.3.0, 2.2.0 > Reporter: Jesus Camacho Rodriguez > Assignee: Jesus Camacho Rodriguez > Priority: Critical > Attachments: HIVE-16102.patch > > > [~ashutoshc] realized that the implementation of GROUPING__ID in Hive was not > returning values as specified by SQL standard and other execution engines. > After digging into this, I found out that the implementation was bogus, as > internally it was changing between big-endian/little-endian representation of > GROUPING__ID indistinctly, and in some cases conversions in both directions > were cancelling each other. > In the documentation in > https://cwiki.apache.org/confluence/display/Hive/Enhanced+Aggregation,+Cube,+Grouping+and+Rollup > we can already find the problem, even if we did not spot it at first. > {quote} > The following query: SELECT key, value, GROUPING__ID, count(\*) from T1 GROUP > BY key, value WITH ROLLUP > will have the following results. > | NULL | NULL | 0 | 6 | > | 1 | NULL | 1 | 2 | > | 1 | NULL | 3 | 1 | > | 1 | 1 | 3 | 1 | > ... > {quote} > Observe that value for GROUPING__ID in first row should be `3`, while for > third and fourth rows, it should be `0`. -- This message was sent by Atlassian JIRA (v6.3.15#6346)