On Tue, Aug 15, 2023 at 1:24 PM Pavel Stehule <pavel.steh...@gmail.com> wrote:
> Hi > > út 15. 8. 2023 v 5:24 odesílatel Andy Fan <zhihui.fan1...@gmail.com> > napsal: > >> >>> jsonb_extract_xx_type just cares about the argtype, but >>> 'explain select xx' will still access the const->constvalue. >>> const->constvalue is 0 which is set by makeNullConst currently, >>> and it is ok for the current supported type. >>> >> >> The exception is numeric data type, the constvalue can't be 0. >> so hack it with the below line. maybe not good enough, but I >> have no better solution now. >> >> + Const *target = >> makeNullConst(fexpr->funcresulttype, >> + >> -1, >> + >> InvalidOid); >> + /* >> + * Since all the above functions are strict, we >> can't input >> + * a NULL value. >> + */ >> + target->constisnull = false; >> + >> + Assert(target->constbyval || target->consttype == >> NUMERICOID); >> + >> + /* Mock a valid datum for !constbyval type. */ >> + if (fexpr->funcresulttype == NUMERICOID) >> + target->constvalue = >> DirectFunctionCall1(numeric_in, CStringGetDatum("0")); >> >> > Personally I think this workaround is too dirty, and better to use a > strict function (I believe so the overhead for NULL values is acceptable). > In the patch v8, I created a new routine named makeDummyConst, which just sits by makeNullConst. It may be helpful to some extent. a). The code is self-document for the user/reader. b). We have a central place to maintain this routine. Besides the framework, the troubles for the reviewer may be if the code has some corner case issue or behavior changes. Especially I have some code refactor when working on jsonb_extract_path. so the attached test.sql is designed for this. I have compared the result between master and patched version and I think reviewer can do some extra testing with it. v8 is the finished version in my mind, so I think it is ready for review now. -- Best Regards Andy Fan
v8-0001-optimize-casting-jsonb-to-a-given-type.patch.bak
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test.sql
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