I have a database of registered users of my site. Every user can update his information, and it goes back to the same place. How should I organise that database so that there won't be any problem with the simultaneous access of multiple users? I am running Apache on Linux, Perl. Can use mSQL, xBase and, of course, plain text or tied hash.
Should I create a "lock" file and wait in a loop until that file is deleted?
Note: the "Users" database is just a sample. Really, I am talking about a file (table) that is being read/updated many times per second, and that's why I expect problems with sharing.