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Thejas M Nair commented on HIVE-5996: ------------------------------------- bq. Now, to answer the same questions, I can give right way, and I have a theory to tell why. It would be great if you can document the theory, otherwise I still would need to look at code to understand the theory ! :) I really appreciate the code cleanup you have been doing. But we have to be careful about backward compatibility. I also agree that we should not burden new users with historic problems. Regarding "Once Hive is stabilized", how do we define that ? Maybe, once we create a list of non backward compatible changes that are important to make, we can make a major release version (1.x) , we can break the backward compatibility of certain things, and document it very well. Hopefully, that list of non-backward compatible changes can be kept small. I discuss this in context of config defaults in HIVE-5875 . > Query for sum of a long column of a table with only two rows produces wrong > result > ---------------------------------------------------------------------------------- > > Key: HIVE-5996 > URL: https://issues.apache.org/jira/browse/HIVE-5996 > Project: Hive > Issue Type: Bug > Components: UDF > Affects Versions: 0.12.0 > Reporter: Xuefu Zhang > Assignee: Xuefu Zhang > Attachments: HIVE-5996.patch > > > {code} > hive> desc test2; > OK > l bigint None > hive> select * from test2; > OK > 6666666666666666666 > 5555555555555555555 > hive> select sum(l) from test2; > OK > -6224521851487329395 > {code} > It's believed that a wrap-around error occurred. It's surprising that it > happens only with two rows. Same query in MySQL returns: > {code} > mysql> select sum(l) from test; > +----------------------+ > | sum(l) | > +----------------------+ > | 12222222222222222221 | > +----------------------+ > 1 row in set (0.00 sec) > {code} > Hive should accommodate large number of rows. Overflowing with only two rows > is very unusable. -- This message was sent by Atlassian JIRA (v6.1.4#6159)