Re: add queryEnv to ExplainOneQuery_hook

On 2018/01/11 21:46, Michael Paquier wrote:
>> I'm surprised we haven't heard any complaints sooner if there are
>> advisors using that hook[1] and expecting to be able to forward to
>> ExplainOnePlan(), but I suppose it would nearly always works to call
>> ExplainOnePlan() with NULL as queryEnv.  It'd currently only be
>> non-NULL for trigger functions running SQL to access transition
>> tables, which is a bit obscure: you'd need to run EXPLAIN inside a
>> suitable trigger function (though in future there might be more ways
>> to create named tuplestore relations).
> 
> It seems to me that QueryEnv should be pushed to the hook, but only on
> HEAD. You surely don't want to break people's extensions after a minor
> upgrade.

Thanks guys! :)

I also surprised that there is no complaint from extension creators.
I suppose that if possible, it would be better to create a unit test
for the hook function to avoid the same bug because there is no contrib
module using ExplainOneQuery_hook in contrib directory.
(It might unnecessary thing, maybe.)

Regards,
Tatsuro Yamada