putenv('TTRSS_ENABLE_UPDATE_DAEMON=true');
        // This enables different mechanism for user-triggered updates designed
        // for update daemon running in background on the server.
        // This option suggests FEEDS_FRAME_REFRESH set to a small value 
        // (like 60 seconds, depending on number of users and server/bandwidth load).

        putenv('TTRSS_DAEMON_SLEEP_INTERVAL=60');
        // Interval between update daemon update runs

        putenv('TTRSS_DAEMON_UPDATE_LOGIN_LIMIT=0');
        // Stop updating feeds of user who haven't logged in specified 
        // amount of days. 0 disables.

        putenv('TTRSS_DAEMON_FEED_LIMIT=60');
        // Limits the amount of feeds daemon (or a cronjob) updates on one run

        putenv('TTRSS_FORCE_ARTICLE_PURGE=0');
        // When this option is not 0, users ability to control feed purging
        // intervals is disabled and all articles (which are not starred) 
        // older than this amount of days are purged.

        putenv('TTRSS_COUNTERS_MAX_AGE=365');
        // Hard limit for unread counters calculation. Try tweaking this
        // parameter to speed up tt-rss when having a huge number of articles
        // in the database (better yet, enable purging!)

        putenv('TTRSS_SIMPLE_UPDATE_MODE=false');
        // Enables fallback update mode where tt-rss tries to update feeds in
        // background while tt-rss is open in your browser. 
        // If you don't have a lot of feeds and don't want to or can't run 
        // background processes while not running tt-rss, this method is generally 
        // viable to keep your feeds up to date.
        // Still, there are more robust (and recommended) updating methods 
        // available, you can read about them here: http://tt-rss.org/wiki/UpdatingFeeds