Re: is JIT available

On Tue, 28 Jul 2020 at 15:33, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> David Rowley <dgrowleyml(at)gmail(dot)com> writes:
> > Maybe this would be better?
>
> > "returns true if jit is enabled and JIT compilation is available in
> > this session (see Chapter 31)."
>
> The general, non-hacker meaning of "jit is enabled" would seem to
> be pretty much what this function is already doing; and for that
> matter, the same can be said for "JIT compilation is available".
> We need something that's less tautological-looking. Maybe along
> the lines of
>
> "returns true if a JIT compiler extension is available and the
> <varname>jit</varname> parameter is set to <literal>on</literal>;

That's probably better. FWIW, the "jit" is already a link to the GUC
docs, so I had in mind that users would have known we meant "jit" the
GUC rather than "jit" the feature. Your wording will help for anyone
who thinks we're talking about the feature.

> when this is true, JIT compilation will be performed."

I'd probably drop this part since it's not really true. The query has
to exceed the cost thresholds before that'll happen.

David