Horton

Re: pgsql: Add more SQL/JSON constructor functions

Amit Langote <amitlangote09@gmail.com>

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From: Amit Langote <amitlangote09@gmail.com>
To: jian he <jian.universality@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Peter Eisentraut <peter@eisentraut.org>, Alvaro Herrera <alvherre@alvh.no-ip.org>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2024-06-28T11:53:31Z
Lists: pgsql-hackers

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On Fri, Jun 28, 2024 at 3:14 PM jian he <jian.universality@gmail.com> wrote:
> On Thu, Jun 27, 2024 at 7:48 PM Amit Langote <amitlangote09@gmail.com> wrote:
> > >
> > > I've attempted that in the attached 0001, which removes
> > > JsonExpr.coercion_expr and a bunch of code around it.
> > >
> > > 0002 is now the original patch minus the changes to make
> > > JSON_EXISTS(), JSON_QUERY(), and JSON_VALUE() behave as we would like,
> > > because the changes in 0001 covers them. The changes for JsonBehavior
> > > expression coercion as they were in the last version of the patch are
> > > still needed, but I decided to move those into 0001 so that the
> > > changes for query functions are all in 0001 and those for constructors
> > > in 0002.  It would be nice to get rid of that coerce_to_target_type()
> > > call to coerce the "behavior expression" to RETURNING type, but I'm
> > > leaving that as a task for another day.
> >
> > Updated 0001 to remove outdated references, remove some more unnecessary code.
> >
>
> i found some remaining references of "coercion_expr" should be removed.
>
> src/include/nodes/primnodes.h
> /* JsonExpr's collation, if coercion_expr is NULL. */
>
>
> src/include/nodes/execnodes.h
> /*
> * Address of the step to coerce the result value of jsonpath evaluation
> * to the RETURNING type using JsonExpr.coercion_expr.  -1 if no coercion
> * is necessary or if either JsonExpr.use_io_coercion or
> * JsonExpr.use_json_coercion is true.
> */
> int jump_eval_coercion;
>
> src/backend/jit/llvm/llvmjit_expr.c
> /* coercion_expr code */
> LLVMPositionBuilderAtEnd(b, b_coercion);
> if (jsestate->jump_eval_coercion >= 0)
> LLVMBuildBr(b, opblocks[jsestate->jump_eval_coercion]);
> else
> LLVMBuildUnreachable(b);
>
>
> src/backend/executor/execExprInterp.c
> /*
>  * Checks if an error occurred either when evaluating JsonExpr.coercion_expr or
>  * in ExecEvalJsonCoercion().  If so, this sets JsonExprState.error to trigger
>  * the ON ERROR handling steps.
>  */
> void
> ExecEvalJsonCoercionFinish(ExprState *state, ExprEvalStep *op)
> {
> }
>
> if (jbv == NULL)
> {
> /* Will be coerced with coercion_expr, if any. */
> *op->resvalue = (Datum) 0;
> *op->resnull = true;
> }
>
>
> src/backend/executor/execExpr.c
> /*
> * Jump to coerce the NULL using coercion_expr if present.  Coercing NULL
> * is only interesting when the RETURNING type is a domain whose
> * constraints must be checked.  jsexpr->coercion_expr containing a
> * CoerceToDomain node must have been set in that case.
> */
>
> /*
> * Jump to coerce the NULL using coercion_expr if present.  Coercing NULL
> * is only interesting when the RETURNING type is a domain whose
> * constraints must be checked.  jsexpr->coercion_expr containing a
> * CoerceToDomain node must have been set in that case.
> */

Thanks for checking.

Will push the attached 0001 and 0002 shortly.

-- 
Thanks, Amit Langote

Commits

  1. SQL/JSON: Avoid initializing unnecessary ON ERROR / ON EMPTY steps

  2. SQL/JSON: Fix default ON ERROR behavior for JSON_TABLE

  3. SQL/JSON: Fix JSON_TABLE() column deparsing

  4. Update comment about ExprState.escontext

  5. SQL/JSON: Fix casting for integer EXISTS columns in JSON_TABLE

  6. SQL/JSON: Some fixes to JsonBehavior expression casting

  7. SQL/JSON: Remove useless code in ExecInitJsonExpr()

  8. SQL/JSON: Respect OMIT QUOTES when RETURNING domains over jsonb

  9. SQL/JSON: Improve error-handling of JsonBehavior expressions

  10. SQL/JSON: Fix error-handling of some JsonBehavior expressions

  11. SQL/JSON: Rethink c2d93c3802b

  12. SQL/JSON: Always coerce JsonExpr result at runtime

  13. SQL/JSON: Fix coercion of constructor outputs to types with typmod