purpose/use of pg_start_backup() pg_stop_backup()

on the surface, the functions pg_start_backup() and pg_stop_backup() seem to
indicate something very useful.

as i understand it, i could do:

psql -c "pg_start_backup('$(date +%Y%m%d%H%M%S)');"
snapshot/dump $PGDATA
psql -c "pg_stop_backup();"

and this would then create a nice clean snapshot.

however, i'm trying to work out what the restore process is.

its not clear to me if one needs to do anything after restoring the dump.

or, if there is some sort of incremental process that needs to be followed
after the dump.

can someone provide a walk-through of using these functions both for
a backup and a restore?

--
Jim Mercer Reptilian Research jim(at)reptiles(dot)org +1 416 410-5633
"He who dies with the most toys is nonetheless dead"