[jira] [Created] (CALCITE-2509) RexSimplify: withParanoid(true).verify takes exponential time as number of variables grows

["Vladimir Sitnikov (JIRA)" <ji...@apache.org>]

Vladimir Sitnikov created CALCITE-2509:
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             Summary: RexSimplify: withParanoid(true).verify takes exponential time as number of variables grows
                 Key: CALCITE-2509
                 URL: https://issues.apache.org/jira/browse/CALCITE-2509
             Project: Calcite
          Issue Type: Bug
          Components: core
    Affects Versions: 1.17.0
            Reporter: Vladimir Sitnikov
            Assignee: Julian Hyde


The most trivial case is {{coalesce(v1, v2, v3,...)}}
For instance, it takes 34 seconds to simplify coalesce with 11 inputs.
{noformat}
1, 2 ms, coalesce(vInt(0))
2, 1 ms, coalesce(vInt(0), vInt(1))
3, 3 ms, coalesce(vInt(0), vInt(1), vInt(2))
4, 13 ms, coalesce(vInt(0), vInt(1), vInt(2), vInt(3))
5, 28 ms, coalesce(vInt(0), vInt(1), vInt(2), vInt(3), vInt(4))
6, 80 ms, coalesce(vInt(0), vInt(1), vInt(2), vInt(3), vInt(4), vInt(5))
7, 184 ms, coalesce(vInt(0), vInt(1), vInt(2), vInt(3), vInt(4), vInt(5), vInt(6))
8, 661 ms, coalesce(vInt(0), vInt(1), vInt(2), vInt(3), vInt(4), vInt(5), vInt(6), vInt(7))
9, 1872 ms, coalesce(vInt(0), vInt(1), vInt(2), vInt(3), vInt(4), vInt(5), vInt(6), vInt(7), vInt(8))
10, 7890 ms, coalesce(vInt(0), vInt(1), vInt(2), vInt(3), vInt(4), vInt(5), vInt(6), vInt(7), vInt(8), vInt(9))
11, 33889 ms, coalesce(vInt(0), vInt(1), vInt(2), vInt(3), vInt(4), vInt(5), vInt(6), vInt(7), vInt(8), vInt(9), vIntNotNull(0))
{noformat}




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