>>> Also, I intentionally dropped the GUC_NO_SHOW_ALL check in >>> get_explain_guc_options, because it seems redundant given >>> the preceding GUC_EXPLAIN check. It's unlikely we'd ever have >>> a variable that's marked both GUC_EXPLAIN and GUC_NO_SHOW_ALL ... >>> but if we did, shouldn't the former take precedence here anyway? > >> You're right, but there's nothing that prevents users writing GUCs >> with GUC_EXPLAIN and GUC_NO_SHOW_ALL. > > "Users"? You do realize those flags are only settable by C code, > right? Moreover, you haven't explained why it would be good that > you can't get at the behavior that a GUC is both shown in EXPLAIN > and not shown in SHOW ALL. If you want "not shown by either", > that's already accessible by setting only the GUC_NO_SHOW_ALL > flag. So I'd almost argue this is a bug fix, though I concede > it's a bit hard to imagine why somebody would want that choice. > Still, if we have two independent flags they should produce four > behaviors, not just three.
I agree that the developer can use both GUC_NO_SHOW_ALL and GUC_EXPLAIN knowingly or unknowingly for a single GUC. If used by mistake then according to the existing code (without patch), GUC_NO_SHOW_ALL takes higher precedence whether it is marked first or last in the code. I am more convinced with this behaviour as I feel it is safer than exposing the information which the developer might not have intended. Thanks & Regards, Nitin Jadhav On Tue, Jan 24, 2023 at 8:43 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > > Bharath Rupireddy <bharath.rupireddyforpostg...@gmail.com> writes: > > On Mon, Jan 23, 2023 at 9:51 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > >> Also, I intentionally dropped the GUC_NO_SHOW_ALL check in > >> get_explain_guc_options, because it seems redundant given > >> the preceding GUC_EXPLAIN check. It's unlikely we'd ever have > >> a variable that's marked both GUC_EXPLAIN and GUC_NO_SHOW_ALL ... > >> but if we did, shouldn't the former take precedence here anyway? > > > You're right, but there's nothing that prevents users writing GUCs > > with GUC_EXPLAIN and GUC_NO_SHOW_ALL. > > "Users"? You do realize those flags are only settable by C code, > right? Moreover, you haven't explained why it would be good that > you can't get at the behavior that a GUC is both shown in EXPLAIN > and not shown in SHOW ALL. If you want "not shown by either", > that's already accessible by setting only the GUC_NO_SHOW_ALL > flag. So I'd almost argue this is a bug fix, though I concede > it's a bit hard to imagine why somebody would want that choice. > Still, if we have two independent flags they should produce four > behaviors, not just three. > > regards, tom lane
