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Posted to dev@calcite.apache.org by Fabian Hueske <fh...@gmail.com> on 2016/02/02 00:13:17 UTC

Expression Validation with RelBuilder

Hi,

I am using Calcite's RelBuilder to directly generate Calcite RelNodes from
Flink Table API calls [1].
The translations works very well and was pretty straightforward to
implement, however it looks like the RelBuilder does not thoroughly
validate the generated expressions.
It ensures that field expressions can be resolved, but does for example not
check the types in expressions (for example it accepts a SUBSTRING(String,
String, Float) expression).

I've seen that Calcite usually validates SQL queries before they are
translated to RelNodes in the SQLNode representation. By calling the
RelBuilder, I am bypassing these phases.

I could implement the checks before calling the RelBuilder myself, but it
would be easier if Calcite could validate the RelNodes and their
expressions. Is this somehow possible?

Thanks, Fabian

[1]
https://ci.apache.org/projects/flink/flink-docs-release-0.10/libs/table.html

Re: Expression Validation with RelBuilder

Posted by Fabian Hueske <fh...@gmail.com>.

Thanks for the quick response and creating the issue.
Let me know if I can help.

Best, Fabian

2016-02-02 3:39 GMT+01:00 Julian Hyde <jh...@apache.org>:

> Agreed, RelBuilder should validate function arguments. I’ve logged
> https://issues.apache.org/jira/browse/CALCITE-1073.
>
> Usually calls are validated using SqlValidator.validateCall, which
> delegates to the following policies inside the operator:
>
>   private final SqlReturnTypeInference returnTypeInference;
>   private final SqlOperandTypeInference operandTypeInference;
>   private final SqlOperandTypeChecker operandTypeChecker;
>
> There isn’t a SqlValidator accessible to RelBuilder, but I think we can
> somehow make RelBuilder call into the policies.
>
> Julian
>
>
>
> > On Feb 1, 2016, at 3:13 PM, Fabian Hueske <fh...@gmail.com> wrote:
> >
> > Hi,
> >
> > I am using Calcite's RelBuilder to directly generate Calcite RelNodes
> from
> > Flink Table API calls [1].
> > The translations works very well and was pretty straightforward to
> > implement, however it looks like the RelBuilder does not thoroughly
> > validate the generated expressions.
> > It ensures that field expressions can be resolved, but does for example
> not
> > check the types in expressions (for example it accepts a
> SUBSTRING(String,
> > String, Float) expression).
> >
> > I've seen that Calcite usually validates SQL queries before they are
> > translated to RelNodes in the SQLNode representation. By calling the
> > RelBuilder, I am bypassing these phases.
> >
> > I could implement the checks before calling the RelBuilder myself, but it
> > would be easier if Calcite could validate the RelNodes and their
> > expressions. Is this somehow possible?
> >
> > Thanks, Fabian
> >
> > [1]
> >
> https://ci.apache.org/projects/flink/flink-docs-release-0.10/libs/table.html
>
>

Re: Expression Validation with RelBuilder

Posted by Julian Hyde <jh...@apache.org>.

Agreed, RelBuilder should validate function arguments. I’ve logged https://issues.apache.org/jira/browse/CALCITE-1073.

Usually calls are validated using SqlValidator.validateCall, which delegates to the following policies inside the operator:

  private final SqlReturnTypeInference returnTypeInference;
  private final SqlOperandTypeInference operandTypeInference;
  private final SqlOperandTypeChecker operandTypeChecker;

There isn’t a SqlValidator accessible to RelBuilder, but I think we can somehow make RelBuilder call into the policies.

Julian



> On Feb 1, 2016, at 3:13 PM, Fabian Hueske <fh...@gmail.com> wrote:
> 
> Hi,
> 
> I am using Calcite's RelBuilder to directly generate Calcite RelNodes from
> Flink Table API calls [1].
> The translations works very well and was pretty straightforward to
> implement, however it looks like the RelBuilder does not thoroughly
> validate the generated expressions.
> It ensures that field expressions can be resolved, but does for example not
> check the types in expressions (for example it accepts a SUBSTRING(String,
> String, Float) expression).
> 
> I've seen that Calcite usually validates SQL queries before they are
> translated to RelNodes in the SQLNode representation. By calling the
> RelBuilder, I am bypassing these phases.
> 
> I could implement the checks before calling the RelBuilder myself, but it
> would be easier if Calcite could validate the RelNodes and their
> expressions. Is this somehow possible?
> 
> Thanks, Fabian
> 
> [1]
> https://ci.apache.org/projects/flink/flink-docs-release-0.10/libs/table.html