I was envisioning running it every night. But real time would work just fine as well.
It's not even close to quadratic in past history. Worst case scenario it would be linear in the daily bets. What a hash table does is provide a lookup mechanism such that in general (with some technical exceptions) the average time for a lookup is independent of the number of items stored. So whether you have a hash table of 10 IP address or 10,000,000, the average time taken to locate a given item will be on average, exactly the same.
To give you an example, using a Perl one-liner on my 3Ghz home PC with 2GB RAM, building a hash table in memory from scratch with 3,000,000 randomly created IP addresses (which is probably 100x more than the number of IP addresses a book would have) takes me about 11 seconds. Searching the table for a 1.1 million different IPs (each of which has a 90% chance of being in the list) takes about 3 seconds.
Building a hash table in memory from scratch with 6,000,000 randomly created IP addresses takes me about 22 seconds. Searching the table for a 1.1 million different IPs (each of which has a 90% chance of being in the list) takes the same 3 seconds.
Also remember that each IP would map to many many bets. Even if a book had 2,000,000 bets in a day it wouldn't mean that that's how many IP addresses it would have. The number of IP addresses would be far, far fewer. Furthermore, each IP address should realistically only be locked in to a certain player for a brief period of time. If you're making bets from the same IP address that someone else used 3 months ago, does that mean a book should be able to confiscate funds? Clearly not.
Books certainly could check for duplicate IP's prior to a player's cashing out if they wanted. Doing so would be absurdly simplistic. For a book with an adequate server and database these checks shouldn't add more than few seconds of additional processor time to their nightly cron jobs. In most cases probably far, far less.
It's clear that books are happy with the status quo. And why shouldn't they be? Encouraging fraud means more money in their pockets, and for the less scrupulous books, it's probably not an insubstantial amount of money either.
It just bothers me immensely when books try to make asinine claims such as this. It's utterly absurd. Books could easily search for multiple players using the same IP address either nightly or in real time. They just don't want to.
It's not even close to quadratic in past history. Worst case scenario it would be linear in the daily bets. What a hash table does is provide a lookup mechanism such that in general (with some technical exceptions) the average time for a lookup is independent of the number of items stored. So whether you have a hash table of 10 IP address or 10,000,000, the average time taken to locate a given item will be on average, exactly the same.
To give you an example, using a Perl one-liner on my 3Ghz home PC with 2GB RAM, building a hash table in memory from scratch with 3,000,000 randomly created IP addresses (which is probably 100x more than the number of IP addresses a book would have) takes me about 11 seconds. Searching the table for a 1.1 million different IPs (each of which has a 90% chance of being in the list) takes about 3 seconds.
Building a hash table in memory from scratch with 6,000,000 randomly created IP addresses takes me about 22 seconds. Searching the table for a 1.1 million different IPs (each of which has a 90% chance of being in the list) takes the same 3 seconds.
Also remember that each IP would map to many many bets. Even if a book had 2,000,000 bets in a day it wouldn't mean that that's how many IP addresses it would have. The number of IP addresses would be far, far fewer. Furthermore, each IP address should realistically only be locked in to a certain player for a brief period of time. If you're making bets from the same IP address that someone else used 3 months ago, does that mean a book should be able to confiscate funds? Clearly not.
Books certainly could check for duplicate IP's prior to a player's cashing out if they wanted. Doing so would be absurdly simplistic. For a book with an adequate server and database these checks shouldn't add more than few seconds of additional processor time to their nightly cron jobs. In most cases probably far, far less.
It's clear that books are happy with the status quo. And why shouldn't they be? Encouraging fraud means more money in their pockets, and for the less scrupulous books, it's probably not an insubstantial amount of money either.
It just bothers me immensely when books try to make asinine claims such as this. It's utterly absurd. Books could easily search for multiple players using the same IP address either nightly or in real time. They just don't want to.