rizaon opened a new pull request #1024: URL: https://github.com/apache/orc/pull/1024
### What changes were proposed in this pull request? This patch is a follow-up of ORC-450. Similar to LIST, we can also avoid the materialization of MAP and UNION column elements by specifying ReadIntent_OFFSETS in selection. This patch also adds a requirement that subtypes of UNION should be all selected or not at all. UnionColumnReader will crash if only part of the subtypes were selected. This patch modifies ColumnSelector to silently select all the UNION subtypes if they were partially selected. ### Why are the changes needed? This patch helps avoid materialization of MAP and UNION elements, such as in the case of "select count(*)" query. ### How was this patch tested? - Added several unit tests under TestReadIntent.* -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
