Effective way how to handle application settings in PL/pgSQL functions - sql

Question

Consider following situation: I have PL/pgSQL function which checks, If given auditor has some prerequisites for QS Auditor function. Thresholds of this prerequisites are defined in separate table quasar_settings. Every time, If is the function called, is executed SELECT which retrieves these prerequisites. This is quite inefficient, because this SELECT is called for every row. This quasar_settings table contains only one row. Is there any other more effective solution (global variable, caching, etc)?
Table quasar_settings has only one row.
Using PostgreSQL 9.3
PL/pgSQL function
CREATE OR REPLACE FUNCTION qs_auditor_training_auditing(auditor quasar_auditor) RETURNS boolean AS $$
DECLARE
settings quasar_settings%ROWTYPE;
BEGIN
SELECT s INTO settings
FROM quasar_settings s LIMIT 1;
RETURN auditor.nb1023_procedures_hours >= settings.qs_auditor_nb1023_procedures AND
-- MD Training
auditor.mdd_hours + auditor.ivd_hours >= settings.qs_auditor_md_training AND
-- ISO 9001 Trainig
(
auditor.is_aproved_for_iso13485 OR
(auditor.is_aproved_for_iso9001 AND auditor.iso13485_hours >= settings.qs_auditor_iso13485_training) OR
(auditor.iso13485_hours + auditor.iso9001_hours >= settings.qs_auditor_class_room_training)
);
END;
$$ LANGUAGE plpgsql;
Example of usage:
SELECT auditor.id, qs_auditor_training_auditing(auditor) FROM quasar_auditor auditor;

Answer 1

Do a cross join to the settings table in instead of calling the function at every row
select
a.id,
a.nb1023_procedures_hours >= s.qs_auditor_nb1023_procedures and
-- md training
a.mdd_hours + a.ivd_hours >= s.qs_auditor_md_training and
-- iso 9001 trainig
(
a.is_aproved_for_iso13485 or
(
a.is_aproved_for_iso9001 and
a.iso13485_hours >= s.qs_auditor_iso13485_training
) or
(a.iso13485_hours + a.iso9001_hours >= s.qs_auditor_class_room_training)
)
from
quasar_auditor a
cross join
quasar_settings s