[HIVE-20100] OpTraits : Select Optraits should stop when a mismatch is detected

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Assignee: Deepak Jaiswal
• Reporter: Deepak Jaiswal
• Created: 05/Jul/18 22:58
• Updated: 11/Jul/18 05:11
• Resolved: 11/Jul/18 05:11

Description

The select operator's optraits logic as stated in the comment is,

// For bucket columns
// If all the columns match to the parent, put them in the bucket cols
// else, add empty list.
// For sort columns
// Keep the subset of all the columns as long as order is maintained.

 

However, this is not happening due to a bug. The bool found is never reset, so if a single match is found, the value remains true and allows the optraits get populated with partial list of columns for bucket col which is incorrect.
This may lead to creation of SMB join which should not happen.