Redshift Compatibility Functions

compat.sql

/* Functions available in Redshift that can be emulated in Postgres for compatibility.
 * This is most applicable when a schema needs to be migrated into a (local) PostgreSQL
 * environment for modeling/development. As Redshift is derived from PostgreSQL, many
 * DBA and related modeling tools designed for PostgreSQL are _not quite_ viable for
 * use with Redshift. These functions attempt to augment native PostgreSQL to allow
 * Redshift SQL to run in other Postges environments.
 * I'll update this periodically with additional functions as needed.
 */

CREATE FUNCTION public.getdate() returns timestamptz
       stable language sql as 'select now()';

CREATE FUNCTION date_diff(text, timestamp, timestamp) returns integer as $$
DECLARE
  span interval := age($2, $3);
BEGIN
  select date_part($1, span);
END
$$ language plpgsql;