Re: Parallel SAFE information missing in CREATE OR REPLACE FUNCTION definition - Mailing list pgsql-hackers

On Tue, Apr 26, 2016 at 1:24 AM, Ashutosh Sharma <ashu.coek88@gmail.com> wrote:
> In PGSQL-9.6, if we create a function with PARALLEL clause and try
> displaying it's definition using "pg_get_functiondef" we see that the
> PARALLEL keyword used during function creation is missing.
>
> Below are the steps to reproduce:
>
> postgres=# CREATE FUNCTION add(integer, integer) RETURNS integer
> postgres-# AS 'select $1 + $2;'
> postgres-# LANGUAGE SQL
> postgres-# PARALLEL SAFE
> postgres-# RETURNS NULL ON NULL INPUT;
> CREATE FUNCTION
>
> postgres=# CREATE OR REPLACE FUNCTION increment(i integer) RETURNS integer
> AS $$
> postgres$#         BEGIN
> postgres$#                 RETURN i + 1;
> postgres$#         END;
> postgres$# $$ LANGUAGE plpgsql PARALLEL SAFE;
> CREATE FUNCTION
>
> postgres=# CREATE FUNCTION square_root(double precision) RETURNS double
> precision
> AS 'dsqrt'
> LANGUAGE internal
> PARALLEL SAFE;
> CREATE FUNCTION
>
> postgres=# \df
>                            List of functions
>  Schema |    Name     | Result data type | Argument data types |  Type
> --------+-------------+------------------+---------------------+--------
>  public | add         | integer          | integer, integer    | normal
>  public | increment   | integer          | i integer           | normal
>  public | square_root | double precision | double precision    | normal
> (3 rows)
>
> postgres=# SELECT  pg_get_functiondef('add'::regproc);
>                    pg_get_functiondef
> ---------------------------------------------------------
>  CREATE OR REPLACE FUNCTION public.add(integer, integer)+
>   RETURNS integer                                       +
>   LANGUAGE sql                                          +
>   STRICT                                                +
>  AS $function$select $1 + $2;$function$                 +
>
> (1 row)
>
> postgres=# SELECT  pg_get_functiondef('increment'::regproc);
>                    pg_get_functiondef
> --------------------------------------------------------
>  CREATE OR REPLACE FUNCTION public.increment(i integer)+
>   RETURNS integer                                      +
>   LANGUAGE plpgsql                                     +
>  AS $function$                                         +
>          BEGIN                                         +
>                  RETURN i + 1;                         +
>          END;                                          +
>  $function$                                            +
>
> (1 row)
>
> postgres=# SELECT  pg_get_functiondef('square_root'::regproc);
>                        pg_get_functiondef
> -----------------------------------------------------------------
>  CREATE OR REPLACE FUNCTION public.square_root(double precision)+
>   RETURNS double precision                                      +
>   LANGUAGE internal                                             +
>  AS $function$dsqrt$function$                                   +
>
> (1 row)
>
>
> RCA: The proparallel information for a function is not considered while
> preparing its definition inside pg_get_functiondef().
>
> Solution: Add a  check for the proparallel flag inside pg_get_functiondef()
> and based on the value in proparallel flag, store the parallel {safe |
> unsafe | restricted} info in the buffer  that holds the function definition.
> PFA patch to fix the issue.

Thanks, committed.  Boy, I feel stupid.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company