Cleaning up directory pgsql_tmp ?

Hi,

I have a 7Go pgsql_tmp directory in my main tablespace which remains
even after a cluster restart.
Does anyone know how to clean up properly ? Can i just delete the
directory in the filesystem (with the cluster up or down ?) ?

The documentation says it should be handled automatically by the
cluster at the next startup, but it does not :(
I guess it comes from a severe server crash that occured several days
ago ...


Thanks in advance !