These commands are permanent.  All deleted data will be lost.  Ensure that you complete a full data backup before proceeding with these commands.

The following commands will delete all performance data prior to a specified date:

delete from performance_aggregate where sample_id <ID; go;
delete from performance_cpu where sample_id <ID; go;
delete from performance_disk where sample_id <ID; go;
delete from performance_esx3_workload where sample_id <ID; go;
delete from performance_fscap where sample_id <ID; go;
delete from performance_network where sample_id <ID; go;
delete from performance_nrm where sample_id <ID; go;
delete from performance_psinfo where sample_id <ID; go;
delete from performance_vmware_workload where sample_id <ID; go;
delete from performance_vxvol where sample_id <ID; go;
delete from performance_who where sample_id <ID; go;