Re: architectural goals, Byte Addressability And Beyond

On Thu, 6 Jun 2024 11:55:22 -0000 (UTC), John Levine wrote:

If you're doing something that is mostly read-only and easy to
parallelize, then it makes sense to use a farm of cheap PCs. But if you
are a bank or an airline, you need to be able to lock your database so
that you debit a bank account or sell a plane seat exactly once.  There
is a rule of thumb that the cost of locking something grows roughly as
the square of the number of things contending for the lock.

Remember that the number of users actually buying a product at any given
time is only a small proportion (say 1%) of the number of users currently
accessing the site.

So, by that same square law, the locking problem is only 1/10,000 as bad
as one might think.