Seriously, DBI and an RDBM can take a programmer to a new level of programming. I recommend any programmer out there who doesn't know how to program with a database learn how to do so very soon. The DBI part is not hard, but setting up and maintaining an RDBM can be. Luckily, there is the wonderful SQLite and the even more wonderful DBD::SQLite that allows you to use SQLite in Perl. One of the greatest benefits of using SQLite is that you get to use SQL, and if you use DBI with DBD::SQLite, then when the time comes to migrate to a "real" RDBM, all you should have to do is simply replace use DBD::SQLite with use DBD::mysql or use DBD::Pg.

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

I was originally going to use a DB_File (Any_DBM, actually) database, but as far as I know, they don't allow for HoHs.

Although, as gjb suggested, you can use MLDBM or you can use Data::Dumper or Storable to serialize your data structure by hand, the truth is that you don't even need an HoH in your case. You are storing the same data for each IP: visits and a timestamp. I would just store the two values in a single scalar delimited by a non-digit character of your choosing. (Consider using a comma, space, colon, semicolon, or pipe symbol as they are all commonly used for this kind of thing.) The right rule of thumb to follow in this case is "keep it simple."

-sauoq
"My two cents aren't worth a dime.";

I've never used it myself, but you could have a go at MLDBM, it should do what you want.

Hope this helps, -gjb-