> my $sth = $dbh->prepare("select sid from v_$session");
Your problem is that you enclosed your SQL statement with double qoutes.
This way, your table name becomes just 'v_' (as there is not any defined
variable $session in your program.) See perl's error message and find
what it is tring to tell you about variable $session.
Please note, that in double quotes, perl does variable expansion so any
character '$' should be escaped.
As an alternative, you could use single quote (or q{}), for example:
my $sth = $dbh->prepare('select sid from v_$session');
or
my $sth = $dbh->prepare(q{select sid from v_$session});
Waldemar
