how can i update radacct_old?

I need a radacct_old table mounthly update and clean radacct. Radacct_old, and radacct_summary are original table? No virus found in this outgoing message. Checked by AVG. Version: 7.5.524 / Virus Database: 270.4.0/1509 - Release Date: 19/06/2008 8:00