PSQL="/opt/pgsql/bin/psql"

echo "********PARALLEL EXECUTION**********"
for a in 0 1 2 3 4 5 6 7 ; do {
	( cat script.sql | sed "s/XX/$a/g"  | $PSQL ) & 
} ; done

wait
echo "********SEQUENTIAL EXECUTION**********"

for a in 0 1 2 3 4 5 6 7 ; do {
	( cat script.sql | sed "s/XX/$a/g"  | $PSQL ) 
} ; done