I have tried to stop it by using 'pg_ctl' and then restart the postmaster, but the problem still exists.
Moreover, I have seen a thread talking about that using pg_dump to export data and then import it again will cause the aolserver unstable. And I also experienced it before. I need to reload the datamodel and the insert statement of data separately. Is there any method can export and then re-import the whole database that will not cause any problem? If not, that would be a nightmare for me...
Besides, is the command "vacuum" helpful?
