我正在尝试在hammerdb中对postgresql进行基准测试，得到以下错误：
Vuser 1:Checkpoint and Vacuum
Error in Virtual User 1: ERROR: must be superuser to do CHECKPOINT
Vuser 1:FINISHED FAILED
Vuser 13:FINISHED SUCCESS
Vuser 18:FINISHED SUCCESS
Vuser 8:FINISHED SUCCESS
Vuser 5:FINISHED SUCCESS
Vuser 21:FINISHED SUCCESS
Vuser 9:FINISHED SUCCESS
Vuser 16:FINISHED SUCCESS
Vuser 20:FINISHED SUCCESS
Vuser 6:FINISHED SUCCESS
Vuser 14:FINISHED SUCCESS
Vuser 19:FINISHED SUCCESS
Vuser 11:FINISHED SUCCESS
Vuser 15:FINISHED SUCCESS
Vuser 17:FINISHED SUCCESS
Vuser 7:FINISHED SUCCESS
Vuser 3:FINISHED SUCCESS
Vuser 10:FINISHED SUCCESS
Vuser 12:FINISHED SUCCESS
Vuser 2:FINISHED SUCCESS
Vuser 4:FINISHED SUCCESS
ALL VIRTUAL USERS COMPLETE
runtimer returned after 416 seconds
vudestroy success
TEST SEQUENCE COMPLETE
解决此问题以及将哪个用户映射为超级用户的任何建议。