[IMPALA-1703] Date/Time functions are very slow

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Duplicate
• Affects Version/s: Impala 2.1
• Component/s: Backend
• Target Version: Product Backlog
• Assignee: Unassigned
• Reporter: Denys Lamanov
• Created: 27/Jan/15 13:42
• Updated: 16/Dec/16 19:12
• Resolved: 16/Dec/16 19:12

Description

Without string function (to_date()):

select `Date`, clusterID, count(*) as 'cnt' from FactDailyUser group by `Date`, clusterID order by 1,3

Result: 21984 records
Execution: 1m 49s

With string function (to_date()):

select to_date(`Date`), clusterID, count(*) as 'cnt' from FactDailyUser group by to_date(`Date`), clusterID order by 1,3

Result: 21984 records
Execution: 9m 9s

Issue Links

• is duplicated by: IMPALA-4055 Investigate and fix to_date() slowness