[IMPALA-9856] Enable result spooling by default

• Type: Task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Impala 4.0.0
• Component/s: Backend
• Epic Color: ghx-label-10
• Assignee: Riza Suminto
• Reporter: Sahil Takiar
• Created: 14/Jun/20 23:39
• Updated: 02/Jul/22 03:27
• Resolved: 03/Mar/21 00:47

Description

Result spooling has been relatively stable since it was introduced, and it has several benefits described in IMPALA-8656. It would be good to enable it by default.

I looked into doing this a while ago, and there are a bunch of tests that rely on the "fetch one row batch at a time" behavior. Those tests fail when result spooling is enabled.

The remaining linked tasks in IMPALA-8656 should be completed as well before enabling result spooling by default.

Issue Links

• relates to: IMPALA-10259 Hit DCHECK in TestImpalaShell.test_completed_query_errors_2
• relates to: IMPALA-10371 test_java_udfs crash impalad if result spooling is enabled
• relates to: IMPALA-10337 DCHECK hit at SpillableRowBatchQueue when row size exceed max reservation
• relates to: IMPALA-8656 Support for eagerly fetching and spooling all query result rows