I am trying to run a stress test on a vector data type table. But not able to run pgbench with custom functions: random_between and random_array. Kindly suggest how to perform the stress test with custom functions.

random_between:

   CREATE OR REPLACE FUNCTION random_between(low INT ,high INT) 
    RETURNS INT AS
    $$
    BEGIN
    RETURN floor(random()* (high-low + 1) + low);
    END;
    $$ language 'plpgsql' STRICT;

random_array:

CREATE OR REPLACE FUNCTION random_array(dim integer)
        RETURNS DOUBLE PRECISION[]
    AS $$
        SELECT array_agg(random())
        FROM generate_series(1, dim);
    $$
    LANGUAGE SQL
    VOLATILE
    COST 1;

Table “public.vtest”

    +------------+-----------------------------+-----------+----------+---------+
    |   Column   |            Type             | Collation | Nullable | Default |
    +------------+-----------------------------+-----------+----------+---------+
    | id         | bigint                      |           |          |         |
    | v          | vector(1536)                |           |          |         |
    | created_at | timestamp without time zone |           |          | now()   |
    +------------+-----------------------------+-----------+----------+---------+

cat simple-read-write.sql

  set id random_between(1, 100000)
  set v random_array(1536)::VECTOR(1536)

    BEGIN;
    --UPDATE 
    UPDATE vtest SET v = :v WHERE id = :id;
    --SELECT 
    SELECT v FROM vtet WHERE id = :id;
    --INSERT 
    INSERT INTO vtest (id,v,created_at) VALUES (:id, :v, CURRENT_TIMESTAMP);
    END;

Pgbench command:

/usr/pgsql-14/bin/pgbench -f ./simple-read-write.sql -c2 -T10 -P1 -U postgres -p 5432 -d pgvector

Error:

set id random_between(1, 100000)
                     ^ error found here
set v random_array(1536)::VECTOR(1536)
                         ^ error found here

Expecting to run pgbench with custom functions and custom sql script.