Created job_log_clear() function to clear log data previous to a give…

…n interval. Logs it too! Made foreign key in job_detail ON DELETE CASCADE.

doc/pg_jobmon.md

@@ -41,6 +41,10 @@ LOGGING
     p_sql is the full sql query to be run.  
     Returns the job id that was created for this job and whether the job was successful.
 
+*job_log_clear(p_interval interval) RETURNS void*  
+    Deletes all jobs in job_log and job_detail tables older than the given interval.
+    Also logs this task as another job itself.
+
 The below functions all return full rows of the format for the given SETOF table, which means you can treat them as tables as far as filtering the result. For all functions that have a default integer parameter at the end, this signifies a default limit on the number of rows returned. You can change this as desired, or just leave out that parameter to get the default limit.  
 All show functions also automatically uppercase the job name parameter to be consistent with the add_job function.
 

sql/pg_jobmon.sql

@@ -35,7 +35,7 @@ CREATE TABLE job_detail (
     status text,
     message text,
     CONSTRAINT job_detail_step_id_pkey PRIMARY KEY (step_id),
-    CONSTRAINT job_detail_job_id_fkey FOREIGN KEY (job_id) REFERENCES job_log(job_id)
+    CONSTRAINT job_detail_job_id_fkey FOREIGN KEY (job_id) REFERENCES job_log(job_id) ON DELETE CASCADE
 );
 CREATE INDEX job_detail_job_id_idx ON job_detail (job_id);
 CREATE SEQUENCE job_detail_step_id_seq
@@ -737,3 +737,48 @@ BEGIN
     RETURN;
 END
 $$;
+
+
+/*
+ *  Delete jobs from job_log and job_detail table older than a given interval.
+ *  Also logs this job purging task.
+ */
+CREATE FUNCTION job_log_clear(p_interval interval) RETURNS void
+    LANGUAGE plpgsql
+    AS $$
+DECLARE
+
+    v_boundary      timestamptz;
+    v_job_id        bigint;
+    v_rowcount      bigint;
+    v_step_id       bigint;
+
+BEGIN
+
+v_boundary := now() - p_interval;
+v_job_id := @extschema@.add_job('Purging pg_jobmon job logs older than '|| v_boundary);
+v_step_id := @extschema@.add_step(v_job_id,'Purging pg_jobmon job logs older than '|| v_boundary);
+
+DELETE FROM @extschema@.job_log WHERE start_time <= v_boundary;
+
+GET DIAGNOSTICS v_rowcount = ROW_COUNT;
+IF v_rowcount > 0 THEN
+    RAISE NOTICE 'Deleted % rows from job_log and associated rows in job_detail', v_rowcount;
+    PERFORM @extschema@.update_step(v_step_id, 'OK', 'Deleted '||v_rowcount||' rows from job_log and associated rows in job_detail');
+ELSE
+    RAISE NOTICE 'No jobs logged older than %', v_boundary;
+    PERFORM @extschema@.update_step(v_step_id, 'OK', 'No jobs logged older than '|| v_boundary);
+END IF;
+PERFORM @extschema@.close_job(v_job_id);
+RETURN;
+
+EXCEPTION
+    WHEN OTHERS THEN
+        IF v_step_id IS NULL THEN
+            v_step_id := @extschema@.add_step(v_job_id, 'EXCEPTION before first step logged');
+        END IF;
+        PERFORM @extschema@.update_step(v_step_id, 'CRITICAL', 'ERROR: '||coalesce(SQLERRM,'unknown'));
+        PERFORM @extschema@.fail_job(v_job_id);
+        RAISE EXCEPTION '%', SQLERRM;
+END;
+$$ 

updates/pg_jobmon--0.4.0--0.4.1.sql

@@ -0,0 +1,47 @@
+-- Created job_log_clear() function to clear log data previous to a given interval. Logs it too!
+-- Fixed job_detail table to have ON DELETE CASCADE foreign key to make this function easier to write
+
+ALTER TABLE @extschema@.job_detail ADD CONSTRAINT job_detail_job_id_fkey_new FOREIGN KEY (job_id) REFERENCES @extschema@.job_log(job_id) NOT VALID;
+ALTER TABLE @extschema@.job_detail DROP CONSTRAINT job_detail_job_id_fkey;
+ALTER TABLE @extschema@.job_detail ADD CONSTRAINT job_detail_job_id_fkey FOREIGN KEY (job_id) REFERENCES @extschema@.job_log(job_id) ON DELETE CASCADE;
+ALTER TABLE @extschema@.job_detail DROP CONSTRAINT job_detail_job_id_fkey_new;
+
+CREATE FUNCTION job_log_clear(p_interval interval) RETURNS void
+    LANGUAGE plpgsql
+    AS $$
+DECLARE
+
+    v_boundary      timestamptz;
+    v_job_id        bigint;
+    v_rowcount      bigint;
+    v_step_id       bigint;
+
+BEGIN
+
+v_boundary := now() - p_interval;
+v_job_id := @extschema@.add_job('Purging pg_jobmon job logs older than '|| v_boundary);
+v_step_id := @extschema@.add_step(v_job_id,'Purging pg_jobmon job logs older than '|| v_boundary);
+
+DELETE FROM @extschema@.job_log WHERE start_time <= v_boundary;
+
+GET DIAGNOSTICS v_rowcount = ROW_COUNT;
+IF v_rowcount > 0 THEN
+    RAISE NOTICE 'Deleted % rows from job_log and associated rows in job_detail', v_rowcount;
+    PERFORM @extschema@.update_step(v_step_id, 'OK', 'Deleted '||v_rowcount||' rows from job_log and associated rows in job_detail');
+ELSE
+    RAISE NOTICE 'No jobs logged older than %', v_boundary;
+    PERFORM @extschema@.update_step(v_step_id, 'OK', 'No jobs logged older than '|| v_boundary);
+END IF;
+PERFORM @extschema@.close_job(v_job_id);
+RETURN;
+
+EXCEPTION
+    WHEN OTHERS THEN
+        IF v_step_id IS NULL THEN
+            v_step_id := @extschema@.add_step(v_job_id, 'EXCEPTION before first step logged');
+        END IF;
+        PERFORM @extschema@.update_step(v_step_id, 'CRITICAL', 'ERROR: '||coalesce(SQLERRM,'unknown'));
+        PERFORM @extschema@.fail_job(v_job_id);
+        RAISE EXCEPTION '%', SQLERRM;
+END;
+$$