#!/bin/bash

cd /tmp

DATE=`date +%Y-%m-%d_%H:%M:%S`
POSTGRES_DATABASES=$(su postgres -c ' psql -t -A -c "SELECT datname FROM pg_database"' | grep -v 'postgres\|template0\|template1')
{
    for DATABASE in $POSTGRES_DATABASES
    do
        echo -n $DATABASE' size - '
        su postgres -c "psql -t -A -c \"SELECT pg_size_pretty( pg_database_size( '$DATABASE' ) );\""
    done
}|sort > /tmp/pg_size_$DATE.res

{ echo '----------------- '
echo -n 'All databases size - '
su postgres -c "psql -t -A -c \"SELECT pg_size_pretty(sum(pg_database_size(datname))) FROM pg_database;\""
} >>  /tmp/pg_size_$DATE.res