All the above are on the right track. But here's is what I got from a consultant that worked perfectly. DISCLAIMER: This will delete ALL tickets, no matter status.
Execute 2 commands on the Primary server cmd prompt.
pdm_extract Call_Req > Call_Req_BKP.dat
pdm_load –f Call_Req_BKP.dat -r
The first command, as you know does an extract of the records in the CR table to a file. The second command then reloads that data back in, but using the (-r) actually is removing that data from the table, therefore deleting the records. As a backup, just in case something goes wrong, you always have that .dat file it created. Do the above commands for the CR, Act_Log and Notify_Log_Header tables. I performed the above actions and it worked perfectly.