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Posted to issues@calcite.apache.org by "Mihai Budiu (Jira)" <ji...@apache.org> on 2023/06/29 17:42:00 UTC

[jira] [Created] (CALCITE-5811) Error messages produced for constant out-of-bounds arguments are confusing

Mihai Budiu created CALCITE-5811:
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             Summary: Error messages produced for constant out-of-bounds arguments are confusing
                 Key: CALCITE-5811
                 URL: https://issues.apache.org/jira/browse/CALCITE-5811
             Project: Calcite
          Issue Type: Bug
    Affects Versions: 1.34.0
            Reporter: Mihai Budiu


Supplying arguments that are out-of-bounds for functions can produce uninformative messages. Consider this test case that can be added to SqlOperatorTest.checkSubstringFunction():
{code:java}
    f.checkString("substring('abc' from 2 for 2147483650)",
        "bc", "VARCHAR(3) NOT NULL");
{code}
The signature of the substring function requires int arguments. The constant 2147483650 is out of bounds for an integer. This causes the test to fail with the following exception:
{code:java}
Error while executing SQL "values (substring('abc' from 2 for 2147483650))": Unable to implement EnumerableCalc(expr#0=[{inputs}], expr#1=['abc'], expr#2=[2], expr#3=[2147483650:BIGINT], expr#4=[SUBSTRING($t1, $t2, $t3)], EXPR$0=[$t4]): rowcount = 1.0, cumulative cost = {2.0 rows, 7.0 cpu, 0.0 io}, id = 153424
  EnumerableValues(tuples=[[{ 0 }]]): rowcount = 1.0, cumulative cost = {1.0 rows, 1.0 cpu, 0.0 io}, id = 153408
{code}
I suspect this happens because of a combination of features:
 - type inference does not reject the call to substring, although the inferred type of the argument is probably bigint
 - an attempt to evaluate the constant function fails because of some overflow
 - the detailed exception about the overflow is lost when handling the error

I suspect this is a deeper problem which may affect all functions, and it is really about type inference and implicit cast insertion.

I can imagine two possible implementation strategies:
 - Postgres rejects such a call because the substring function cannot take a bigint argument
 - The compiler could add an implicit cast from bigint to int, which should at least give a warning because the value is too large to fit in an integer

Both these solutions would avoid a crash in the expression evaluation. I personally do not yet understand well enough the type inference mechanisms in Calcite to propose a solution.

To make matters worse, some SQL dialects have substring functions with bigint arguments. In this case there should be two different substring functions, with different signatures.

This issue surfaced during a discussion for [https://github.com/apache/calcite/pull/3286,] and is related to https://issues.apache.org/jira/browse/CALCITE-5810.

 



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