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https://issues.apache.org/jira/browse/CALCITE-525?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16643796#comment-16643796
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Julian Hyde commented on CALCITE-525:
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I saw [~vlsi]'s comments on the PR, but let's bring the discussion to this JIRA.
I do see why you want to add a public API - people need to customize how
exceptions are handled. One person (or engine) might want to abort a query on
divide-by-zero, another might want to convert it to null.
Some of the strategy can occur at code-generation time (and could therefore
apply to engines other than Enumerable) but you are correct that we need some
runtime support.
I like how you have created an ExceptionHandler class and added it to
DataContext, and how you have created some default implementations in an enum.
I would mark these APIs experimental using annotations, as [~vlsi] suggests.
Can you rename ExceptionHandlerUtil to ExceptionHandlers, per current
conventions for companion objects.
Thanks for the comprehensive tests.
I'll do a detailed review when we have achieved consensus on the specification.
> Exception-handling in built-in functions
> ----------------------------------------
>
> Key: CALCITE-525
> URL: https://issues.apache.org/jira/browse/CALCITE-525
> Project: Calcite
> Issue Type: Bug
> Reporter: Julian Hyde
> Assignee: Hongze Zhang
> Priority: Major
>
> The standard calls for certain built-in functions to throw exceptions.
> Examples:
> * 1 / 0
> * MOD(1, 0)
> * OVERLAY('foo' PLACING 'x' FROM -1)
> * 'x' NOT LIKE 'x' ESCAPE 'x'
> First, these exceptions should occur at run time. They should cause the
> current value to become null, or the row to be omitted, but should not abort
> the query. (Actual behavior TBD.)
> Second, EnumerableCalc does constant reduction and generates code like
> 'static final int X = 0 / 0'. This code blows up when the class is loaded. It
> should not. The code should give errors for each row, as described above.
> While fixing this bug, see SqlOperatorBaseTest.testArgumentBounds and remove
> restrictions related to /, MOD and OVERLAY, LIKE.
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