Poor Large input first query performance

[Huararanga]

Summary

We are refactoring from V4.
When we use large inputs, we are observing poor pefrormance for first query.

Steps to reproduce

Follow steps in readme https://github.com/Huararanga/postgraphile-large-input

Expected results

Good pefrormance on first query call

Actual results

Poor pefrormance on first query call

Additional context

[Huararanga]

As @benjie suggested switching from

const $input = fieldArgs.get("input");

to

const $input = fieldArgs.getRaw("input");

fixed for this case

[benjie]

A reproduction courtesy of @slaskis:

psql <<SQL
    DROP SCHEMA IF EXISTS a;
    CREATE SCHEMA a;

    CREATE TABLE a.ev (
        id serial primary key,
        input jsonb
    );

    CREATE FUNCTION a.insert_ev(evs a.ev[]) RETURNS void
        LANGUAGE sql
    AS $$
        INSERT INTO a.ev
            (id, input)
        SELECT
            new_ev.id,
            new_ev.input
        FROM
            UNNEST(insert_ev.evs) AS new_ev
        ON CONFLICT DO NOTHING;
    $$;
SQL

npx pgl@beta -P pgl/amber --connection "postgres://postgres@localhost:5432/test" --schema a

node -p 'JSON.stringify({query: "mutation MyMutation($input: InsertEvInput!) {insertEv(input: $input) {clientMutationId}}", variables: {input: {evs: Array.from(Array(1000)).map((_, i) => ({rowId:i,input:{a:123}}))}}})' | \
curl 'http://\[::\]:5678/graphql' \
  -H 'accept: application/json, multipart/mixed' \
  -H 'content-type: application/json' \
  -d @-