snowflake-create-external-function

Before writing a CREATE EXTERNAL FUNCTION statement:

1. Read references/parameters.md to review all available parameters and their defaults.
2. For each parameter, decide whether the user's request implies a non-default value.
3. Include only the parameters that differ from the default or that the user explicitly requested.
4. Never use CREATE OR REPLACE — always use CREATE EXTERNAL FUNCTION IF NOT EXISTS where supported (note: IF NOT EXISTS is not supported for external functions — omit it and warn the user).
5. API_INTEGRATION and the AS '<url>' clause are always required; ensure both are present.
6. Set MAX_BATCH_ROWS explicitly when the remote service has a documented row-per-request limit.
7. Use RETURNS NULL ON NULL INPUT when the remote endpoint cannot handle NULL payloads.
8. Prefer COMPRESSION = NONE during development to simplify payload inspection; switch to AUTO (default) for production.
9. Use REQUEST_TRANSLATOR / RESPONSE_TRANSLATOR UDFs to adapt the Snowflake row-array envelope to/from custom API schemas.