Re: Using Expanded Objects other than Arrays from plpgsql

Hi, Tom!

On Mon, 3 Feb 2025 at 21:53, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> Pavel Borisov <pashkin(dot)elfe(at)gmail(dot)com> writes:
> > Minor notes on the patches:
>
> > If dump_* functions could use the newly added walker, the code would
> > look better. I suppose the main complication is that dump_* functions
> > contain a lot of per-statement prints/formatting. So maybe a way to
> > implement this is to put these statements into the existing tree
> > walker i.e. plpgsql_statement_tree_walker_impl() and add an argument
> > bool dump_debug into it. So in effect called with dump_debug=false
> > plpgsql_statement_tree_walker_impl() would walk silent, and with
> > dump_debug=false it would walk and print what is supposed to be
> > printed currently in dump_* functions. Maybe there are other problems
> > besides this?
>
> I'm not thrilled with that idea, mainly because it would add overhead
> to the performance-relevant cases (mark and free) to benefit a rarely
> used debugging feature. I'm content to leave the debug code out of
> this for now --- it seems to me that it's serving a different master
> and doesn't have to be unified with the other routines.
Makes sense.

> > For exec_check_rw_parameter():
>
> > I think renaming expr->expr_simple_expr to sexpr saves few bytes but
> > doesn't makes anything simpler, so if possible I'd prefer using just
> > expr->expr_simple_expr with necessary casts. Furtermore in this
> > function mostly we use cast results fexpr, opexpr and sbsref of
> > expr->expr_simple_expr that already has separate names.
>
> Hmm, I thought it looked cleaner like this, but I agree beauty
> is in the eye of the beholder. Anybody else have a preference?
>
> > Transferring target param as int paramid looks completely ok. But we
> > have unconditional checking Assert(paramid == expr->target_param + 1),
> > so it looks as a redundant split as of now. Do we plan a true split
> > and removal of this assert in the future?
>
> We've already fetched the target variable using the paramid (cf
> plpgsql_param_eval_var_check), so I think checking that the
> expression does match it seems like a useful sanity check.
> Agreed, it shouldn't ever not match, but that's why that's just
> an Assert.
There are no problems with these.

Regards,
Pavel Borisov