st 7. 8. 2019 v 18:39 odesÃlatel Tom Lane <t...@sss.pgh.pa.us> napsal:
> Pavel Stehule <pavel.steh...@gmail.com> writes: > > st 7. 8. 2019 v 17:39 odesÃlatel Tom Lane <t...@sss.pgh.pa.us> napsal: > >> I wouldn't trust that. You don't really know what the lifespan of > >> a fn_extra cache is. > > > fn_extra cache cannot be longer than query. > > There are fn_extra caches that are not tied to queries. Admittedly > they're for special purposes like I/O functions and index support > functions, and maybe you can assume that your function can't be > used in such ways. I don't think it's a great programming model > though. > > > And if I understand well, then > > is not possible to change parameter types inside query? > > Most places dealing with composite types assume that the rowtype *could* > change intraquery. I believe this was a live possibility in the past, > though it might not be today. (The issue was inheritance queries, but > I think we now force tuples from child tables to be converted to the > parent rowtype. Whether that's 100% bulletproof is unclear.) If you're > not dealing with composites then it's an okay assumption. I think. > ok, thank you for your reply. Regards Pavel > regards, tom lane >
