Welcome, your post lacks sufficient details to help us help you. Are you trying to automate sqlplus rather than use DBI/DBD::Oracle? It sounds as though your code is using . which is for string concatenation:

my $foo = 'ba';
my $bar = 'z';
print $foo . $bar;
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As others have said it would be better to post the code you are using which shows us the problem, or at least a minimal example which can be used to replicate the problem. How do I post a question effectively? is worth reading if you have not already done so.