po 25. 1. 2021 v 8:05 odesÃlatel Joel Jacobson <j...@compiler.org> napsal:
> Hi, > > I'm trying to understand how pg_proc.protrftypes works. > > The documentation says "Data type OIDs for which to apply transforms.". > For this column, there is no reference to any catalog table? > I would guess it should be "(references pg_type.oid)", right? > > I tried to generate a value for this column to verify my hypothesis, > but I struggle to find an example that produces a not null value here. > > I grepped the sources and found the "CREATE TRANSFORM FOR type_name" > command, > and found an extension using it named "bool_plperl" which I installed. > > I assumed this would cause a value, but no. > > Both of bool_plperl's two functions get null pg_proc.protrftypes values. > > I've tried running the full regression "make installcheck", > but protrftypes doesn't seem to be covered: > > $ cd postgresql > $ make installcheck > ... > ======================= > All 203 tests passed. > ======================= > $ psql regression > regression=# SELECT COUNT(*) FROM pg_proc WHERE protrftypes IS NOT NULL; > count > ------- > 0 > (1 row) > > Can someone please show me how to generate a function with a not null > pg_proc.protrftypes value? > you should to use TRANSFORM clause in CREATE FUNCTION statement https://www.postgresql.org/docs/current/sql-createfunction.html CREATE EXTENSION hstore_plperl CASCADE; CREATE FUNCTION test2() RETURNS hstore LANGUAGE plperl TRANSFORM FOR TYPE hstore AS $$ $val = {a => 1, b => 'boo', c => undef}; return $val; $$; Regards Pavel > Many thanks. > > /Joel > > > > > > >
