[LENS-603] Skip expression rewrite in columnar rewriter

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.2
• Component/s: driver-jdbc
• Assignee: SushilMohanty
• Reporter: SushilMohanty
• Created: 12/Jun/15 05:59
• Updated: 03/Jul/15 14:14
• Resolved: 19/Jun/15 06:40

Description

There are certain cases where expressions has conditions which needs to be applied for each resultant row. For eg. sum(case when city_dim.city_name = 'abc' then total_count when city_dim.city_name is null then 0 end) . Columnar rewriter is rewriting such expression as fact subquery and passing the result to main query. We should skip such rewrite and do it only once in the main query.