<programlisting>

CREATE OR REPLACE PROCEDURE cs_create_job(v_job_id IN INTEGER) IS

a_running_job_count INTEGER;

PRAGMA AUTONOMOUS_TRANSACTION;<co id="co.plpgsql-porting-pragma">

PRAGMA AUTONOMOUS_TRANSACTION; --<co id="co.plpgsql-porting-pragma">

BEGIN

LOCK TABLE cs_jobs IN EXCLUSIVE MODE;<co id="co.plpgsql-porting-locktable">

LOCK TABLE cs_jobs IN EXCLUSIVE MODE; --<co id="co.plpgsql-porting-locktable">

SELECT count(*) INTO a_running_job_count FROM cs_jobs WHERE end_stamp IS NULL;

IF a_running_job_count &gt; 0 THEN

COMMIT; -- free lock<co id="co.plpgsql-porting-commit">

COMMIT; -- free lock<co id="co.plpgsql-porting-commit">

raise_application_error(-20000,

'Unable to create a new job: a job is currently running.');

END IF;

SELECT count(*) INTO a_running_job_count FROM cs_jobs WHERE end_stamp IS NULL;

IF a_running_job_count &gt; 0 THEN

RAISE EXCEPTION 'Unable to create a new job: a job is currently running';<co id="co.plpgsql-porting-raise">

RAISE EXCEPTION 'Unable to create a new job: a job is currently running'; --<co id="co.plpgsql-porting-raise">

END IF;

DELETE FROM cs_active_job;

BEGIN

INSERT INTO cs_jobs (job_id, start_stamp) VALUES (v_job_id, now());

EXCEPTION

WHEN unique_violation THEN <co id="co.plpgsql-porting-exception">

WHEN unique_violation THEN--<co id="co.plpgsql-porting-exception">

-- don't worry if it already exists

END;

END;

<programlisting>

SELECT city, max(temp_lo)

FROM weather

WHERE city LIKE 'S%'<co id="co.tutorial-agg-like">

WHERE city LIKE 'S%' --<co id="co.tutorial-agg-like">

GROUP BY city

HAVING max(temp_lo) &lt; 40;

</programlisting>