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Daniel Dai edited comment on HIVE-20095 at 7/12/18 6:25 AM: ------------------------------------------------------------ Haven't read through the patch but the motivation of the change in HIVE-19161 is to rely on table schema rather than ResultSet to determine the object type of the results. Same sql expression could be interpreted as different datatype in ResultSet for different databases, thus the result for the same expression could be different datatype for different database. Rely on table schema is more reliable. I don't remember a concrete example out of my head but there must be on inside hive-schema-3.1.0.hive.sql. I can find it if needed. I am not sure how this breaks PPD, is that "hiveQueryExecution" part in JdbcSerDe? If we can fix it and keep rely on table schema for result type, that should be fine for me. was (Author: daijy): Haven't read through the patch but the motivation of the change in HIVE-19161 is to rely on table schema rather than ResultSet to determine the object type of the results. Same sql expression could be interpreted as different datatype in ResultSet for different databases, thus the result for the same expression could be different datatype for different database. Rely on table schema is more reliable. I don't have a concrete example out of my head but I can find one if needed. I am not sure how this breaks PPD, is that "hiveQueryExecution" part in JdbcSerDe? > Fix jdbc external table feature > ------------------------------- > > Key: HIVE-20095 > URL: https://issues.apache.org/jira/browse/HIVE-20095 > Project: Hive > Issue Type: Bug > Reporter: Jonathan Doron > Assignee: Jonathan Doron > Priority: Major > Attachments: HIVE-20095.1.patch, HIVE-20095.2.patch, > HIVE-20095.3.patch > > > It seems like the committed code for HIVE-19161 > (7584b3276bebf64aa006eaa162c0a6264d8fcb56) reverted some of HIVE-18423 > updates, and therefore some of the external table queries are not working > correctly. -- This message was sent by Atlassian JIRA (v7.6.3#76005)