According to the postgresql 8 manual, before starting a base backup (i.e. copying the files out of the data directory), you need to issue a command like this:
psql -d DATABASENAME -c "SELECT pg_start_backup('label');
But, since the postgresql files in the data directory contain ALL databases held by postgresql, what is the point of specifying DATABASENAME? (eg: mydb). Is it equally effecting to just use template0 as the databasename?