With devel/php you can go to some site and quickly found out value of some variable in DB that might concern you. So to do that you can go and write
$value='name_of_field';
$query = db_query('SELECT * FROM {system} s WHERE s.name = :name', array(':name' => $name_of_field));
$result = $query->fetchAll();
foreach ($result as $record) {
dpm( $record);
}
and you will get a dump of values of particular field in particular DB table (in here its system table).
If you want to make some fuzzy searches, than you can use LIKE in query so you do this
$search_string ="site_deployment";
$result = db_query('SELECT *
FROM {system} s
WHERE s.name like :name'
,array(':name' => "%".$search_string."%"))
->fetchAll();
foreach ($result as $record) {
dpm( $record);
}