Maybe the hash could be a perl hash:

%database_index;
# Run me once
my $idx=0;
for (@database) {
    $database_index{$_} = $idx++;
}
# /Run me once
# good candidate for a BEGIN block - caveat dynamic
# This is pretty standard and not best for all situations
[download]

Now $database_index{'query'} gives you what you want. This must be run again if the database changes, so it's awkward for dynamic situations.

After Compline
Zaxo