If this optional parameter is set to non-zero, it specifies
the time period in seconds that PLMNDatabaseSQL
uses
to refresh the PLMN information by rereading the database. If set to 0,
then PLMN information is only read from the database once at startup and
on SIGHUP. Defaults to 0. The % formats are permitted.
When the
RefreshPeriod
expires and the information is read
from the SQL database, all previously read information is replaced with
the SQL information. When information from SQL can not be completely read,
the old information is kept. Refresh from the SQL is attempted again when
the refresh period elapses the next time.
# Reread the PLMN information every hour
RefreshPeriod 3600