[HIVE-2248] Comparison Operators convert number types to common type instead of double if possible

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.8.0
• Component/s: Query Processor
• Hadoop Flags: Reviewed
• Assignee: Siying Dong
• Reporter: Siying Dong
• Created: 30/Jun/11 23:04
• Updated: 16/Dec/11 23:56
• Resolved: 01/Jul/11 01:53

Description

Now if the two sides of comparison is of different type, we always convert both to double and compare. It was a slight regression from the change in https://issues.apache.org/jira/browse/HIVE-1638. The old UDFOP<Comparison>, using GenericUDFBridge, always tried to find common type first.

The worse case is this: If you did "WHERE <BIGINT_COLUMN> = 0 ", we always convert the column and 0 to double and compare, which is wasteful, though it is usually a minor costs in the system. But it is easy to fix.