Re: Bug (8.4beta): FailedAssertion("!(bms_is_subset(relids, qualscope))", File: "initsplan.c", Line: 915)

Tom Lane wrote:

> Oh!  What is happening is that to_number(1) is being reduced to constant
> NULL, whereupon it concludes that ad_tab_id=to_number(1) is constant
> NULL, ergo the EXISTS can never succeed, ergo the entire WHERE is
> constant false.

> CREATE FUNCTION to_number(integer) RETURNS numeric
>     LANGUAGE plpgsql IMMUTABLE
>     AS $_$
> BEGIN
> RETURN to_number($1, 'S99999999999999D999999');
> EXCEPTION
>   WHEN OTHERS THEN
>     RETURN NULL;
> END;
> $_$;

How can the executor "see through" a plpgsql function definition?  Or do
you mean that this reduction is being done at execution time?  (hmm ...
this is what a one-time filter is, now that I think about it?)

--
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.