Thread: The mysterious pg_proc.protrftypes

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?

Many thanks.

/Joel

On Mon, Jan 25, 2021, at 08:14, Pavel Stehule wrote:

>you should to use TRANSFORM clause in CREATE FUNCTION statement

Thanks, it worked, and like expected it references the pg_type.oid of the transform.

Attached patch adds "(references pg_type.oid)" to the documentation for pg_proc.protrftypes.

Suggested commit message: "Document the fact that pg_proc.protrftypes references pg_type.oid"

/Joel