Rsyslog supports writing to the database. Like with log files, the rsyslogd writes the data, but does not delete (or export) it. If you need the data only for a period of time, simply deleting excess data might be a workable solution.
Below are some examples how this can be done (thanks to Michael Meckelein for posting this in the forum):
You can start a script via cron job, e. g.
mysql -u database-userid -pdatabase-password -e "truncate table SystemEvents" database-name
to delete all data or like
mysql -u database-userid -pdatabase-password -e "DELETE FROM SystemEvents WHERE ReceivedAt < date_add(current_date, interval -1 day)" database-name
to delete data older than one day.