zabetak commented on pull request #2071: URL: https://github.com/apache/hive/pull/2071#issuecomment-819474363
> > 3. What are the semantics of the comparisons? Are we following the SQL standard? > > I am not aware of any SQL standards for complex type comparison. The join ordering used follows the normal comparison, equality is check from left to right fields. The SQL standard covers comparisons for STRUCT and ARRAY types. LIST are not covered but they should be identical to ARRAY. MAP type does not exist in the standard but it is basically a specialization of MULTISET type (unordered collection). From what I can see in the PR most of the things so far are aligned with the standard (speaking only for the equals operator (`=`) ) except the MAP type. From my understanding equality between maps should not rely at all on the order of the elements in the data structure. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
