Got a strange notice that PCGS is retiring my old customer number at the end of the year and have stated what the new one will be. Old one was 6 digits; new one is 8. Maybe they have or had 1 million (900 k if they don’t want numbers less than 6 digits) customers and are running out of numbers. 8 digits will allow a billion (900 million if they don’t want numbers less than 8 digits). Mike
Weird. They could keep all the old numbers and just add two digits to their database for when they go above a million. Maybe there's some other reasoning.
Yeah, my first impulse would've been "convert all the old customer numbers by prepending 00", followed by "or by prepending 10 if you're very very stupid about how you display leading zeroes". Maybe they want to avoid the "prestige effect" of low customer numbers representing longer-time customers. Not sure why they'd want to do that, though.
And they're going to have to keep a table of old and new numbers so they can connect the customers to their history. Which means they can still look you up by your old number if they wanted to. Unless they're going to do some sort of global search and replace, which would be fraught with disaster. Oh well, they're not begging for my consultation.
Checked my new customer number again. It’s 9, not 8, digits. That allows PCGS to have 9 billion customers if they want to avoid leading zeros. Enough for everyone on the planet! Avoiding leading zeros is a good idea. They can be handled in house by businesses reasonably well, but customers are a different matter. Most businesses avoid leading zeros. I’ve had many bank and credit card numbers over the years. None started with a zero. My wife once had a time share. Customer number was 12 digits with 5 (or was it 6) leading zeros. Had to count carefully for every transaction. Quiz: How many 9-digit numbers are there that don’t start with zero and do not have any adjacent identical digits? (Example: 945895454 would be OK; 944895454 would not because of the “44”.) Mike
The credit card number is assigned in blocks. The first digit indicates the brand (3 for Amex, 4 for Visa, and 5 for MasterCard). Within Visa and Mastercard, various four-digit initial prefixes are assigned to the issuing banks.
Without worrying about adjacent identical digits I think it would be 900,000,000. Total guess on the adjacent identical digits scenario would be 919,999,999.
My bank account used to start with 09. They got bought and the new bank doesn't have leading zeros, so now it's just 9. It took them a couple days to straighten it out, but now either way works, 09 or 9. It's been 13 years since I retired from database work but I recall this was such an easy thing to accommodate. Just hit the value entered with an integer function - 0123, 00123, 000123 are all the same, 123. It doesn't matter how off you are with the number of leading zeros. They can't be dumb enough to treat them as different customer or account numbers.
Thanks for the correction. My answer was for 10 digits. I should have written it out. Arithmetic is hard! Answer disallowing adjacent repeating digits is 9^9 (9 to the ninth power) which is 387,420,489. There are 9 choices for far left (most significant) because zero is not allowed. For the next digit, zero is allowed, but not the digit to the left, so 9 choices. So on, for the next 7 digits ... 9x9x9x9x9x9x9x9x9 if I counted right. Mike
I'd be inclined to agree - if I hadn't had to deal with quite so many software systems that didn't even trim leading or trailing spaces.
