S'assure qu'une bascule de log est réalisée au moins toutes les semaines.

DECLARE
        v_now                   timestamp;
        v_now_dow               int4;
        v_auto_dow              int4;
        v_auto_time             time;
        v_auto_ts               timestamp;
        v_lastrun               timestamp;
        v_laststart             timestamp;
        v_days_since    int4;
BEGIN
        -- ----
        -- Check that today is the day to run at all
        -- ----
        v_auto_dow := registry_get_int4(
                        'logswitch_weekly.dow', 0);
        v_now := "pg_catalog".now();
        v_now_dow := extract (DOW from v_now);
        if v_now_dow <> v_auto_dow then
                perform registry_set_timestamp(
                                'logswitch_weekly.lastrun', v_now);
                return 0;
        end if;

        -- ----
        -- Check that the last run of this procedure was before and now is
        -- after the time we should automatically switch logs.
        -- ----
        v_auto_time := registry_get_text(
                        'logswitch_weekly.time', '02:00');
        v_auto_ts := current_date + v_auto_time;
        v_lastrun := registry_get_timestamp(
                        'logswitch_weekly.lastrun', 'epoch');
        if v_lastrun >= v_auto_ts or v_now < v_auto_ts then
                perform registry_set_timestamp(
                                'logswitch_weekly.lastrun', v_now);
                return 0;
        end if;

        -- ----
        -- This is the moment configured in dow+time. Check that the
        -- last logswitch was done more than 2 days ago.
        -- ----
        v_laststart := registry_get_timestamp(
                        'logswitch.laststart', 'epoch');
        v_days_since := extract (days from (v_now - v_laststart));
        if v_days_since < 2 then
                perform registry_set_timestamp(
                                'logswitch_weekly.lastrun', v_now);
                return 0;
        end if;

        -- ----
        -- Fire off an automatic logswitch
        -- ----
        perform logswitch_start();
        perform registry_set_timestamp(
                        'logswitch_weekly.lastrun', v_now);
        return 1;
END;