[jira] [Created] (DRILL-4357) Planner max time limit

["Luca Bruno (JIRA)" <ji...@apache.org>]

Luca Bruno created DRILL-4357:
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             Summary: Planner max time limit
                 Key: DRILL-4357
                 URL: https://issues.apache.org/jira/browse/DRILL-4357
             Project: Apache Drill
          Issue Type: Improvement
          Components: Query Planning & Optimization
         Environment: Debian Linux, Drill embedded 1.4, one machine.
            Reporter: Luca Bruno


The plan for this kind of query takes an indefinite amount of time:

SELECT label, AVG(foo) FROM (
  SELECT label, AVG(x) as foo FROM table1 GROUP BY label
  UNION ALL
  SELECT label, AVG(y) as foo FROM table2 GROUP BY label
  UNION ALL
  ... 30 times
) GROUP BY label

That is, the query is not executed at all, because the planning does not finish (we're talking about hours).

By disabling planner.enable_multiphase_agg, the planning completes immediately and the query runs.

But I guess this can happen also for other kind of queries. I'd like to suggest a way to limit the planning time. Once this time elapses, the planner outputs the best plan found so far.



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