Re: SPI/backend equivalent of extended-query Describe(statement)?

Chapman Flack <chap(at)anastigmatix(dot)net> writes:
> On 05/25/18 20:07, Andrew Gierth wrote:
>> /*
>> * GAH. To do parameter type checking properly, we have to install our
>> * own global post-parse hook transiently.
>> */
>> ...
>> PG_TRY();
>> {
>> pllua_spi_prev_parse_hook = post_parse_analyze_hook;
>> post_parse_analyze_hook = pllua_spi_prepare_checkparam_hook;
>> ...
>> PG_CATCH();
>> {
>> post_parse_analyze_hook = pllua_spi_prev_parse_hook;
>> --pllua_spi_prepare_recursion;
>> PG_RE_THROW();
>> ...

> Gah, indeed. Thanks for the heads up. I would never have guessed it'd
> be that fiddly.

Yikes. That seems pretty unsafe :-(

Obviously, I missed a bet by not folding check_variable_parameters
into the pstate hook mechanism. It's a bit late to do anything
about that for v11, but I'd favor trying to improve the situation
in v12.

regards, tom lane