Re: explain plans with information about (modified) gucs

On 1/14/19 11:13 PM, Alvaro Herrera wrote:
> On 2019-Jan-14, Tomas Vondra wrote:
>
>> The one slightly annoying issue is that currently all the options are
>> formatted as text, including e.g. cpu_tuple_cost. That's because the GUC
>> options may have show hook, so I can't access the value directly (not
>> sure if there's an option around it).
>
> I think the problem is that you'd have to know how to print the value,
> which can be in one of several different C types. You'd have to grow
> some more infrastructure in the GUC tables, I think, and that doesn't
> seem worth the trouble. Printing as text seems enough.
>

I don't think the number of formats is such a big issue - the range of
formats is quite limited: PGC_BOOL, PGC_INT, PGC_REAL, PGC_STRING and
PGC_ENUM. But the show hook simply returns string, and I'm not sure it's
guaranteed it matches the raw value (afaik the assign/show hooks can do
all kinds of funny stuff).

regards

--
Tomas Vondra http://www.2ndQuadrant.com
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