RE: Big Performance drop of Exceptions in UDFs between V11.2 and 13.4

["ldh@xxxxxxxxxxxxxxxxxx" <ldh@xxxxxxxxxxxxxxxxxx>]

   >  -----Original Message-----
   >  From: Tom Lane <tgl@xxxxxxxxxxxxx>
   >  Sent: Friday, August 27, 2021 13:43
   >  To: ldh@xxxxxxxxxxxxxxxxxx
   >  Cc: Justin Pryzby <pryzby@xxxxxxxxxxxxx>; Ranier Vilela
   >  <ranier.vf@xxxxxxxxx>; pgsql-performance@xxxxxxxxxxxxxx
   >  Subject: Re: Big Performance drop of Exceptions in UDFs between V11.2
   >  and 13.4
   >  
   >  "ldh@xxxxxxxxxxxxxxxxxx" <ldh@xxxxxxxxxxxxxxxxxx> writes:
   >  > That being said, do you have any suggestion how I could circumvent
   >  the
   >  > issue altogether?
   >  
   >  Based on Andrew's report, it seems like you might be able to work
   >  around it for the time being by disabling message translations, i.e.
   >  	SET lc_messages = 'C';
   >  Even if that's not acceptable in your work environment, it would be
   >  useful to verify that you see an improvement from it.
   >  
   >  			regards, tom lane



SET lc_messages = 'C';
drop table sampletest;
create table sampletest (a varchar, b varchar);
insert into sampletest (a, b)
select substr(md5(random()::text), 0, 15), (100000000*random())::integer::varchar
  from generate_series(1,100000);

CREATE OR REPLACE FUNCTION toFloat(str varchar, val real)
RETURNS real AS $$
BEGIN
  RETURN case when str is null then val else str::real end;
EXCEPTION WHEN OTHERS THEN
  RETURN val;
END;
$$ LANGUAGE plpgsql COST 1 IMMUTABLE;

show lc_messages; -- OK 'C'