permanent storage of PHP variables?

Question

Is it possible to store permanent variables in PHP, i.e. final unmodifiable variables, but which can be read by all users requesting a page?

E.g. I would need to use a dictionary on a page, starting with a big (invariant) word list. What is the best way to do this?

• Converting the word list to a tree on-the-fly on every page load is a total waste of compute resources and requires several seconds per page load.
• Putting the tree in the file system as subfolders and use file_exists() is fast enough but uses 4KB per word, which is a total waste of disk space.
• Putting the words in a database is unworkable as I need thousands of lookups per page load.

What would be the proper way to store this dictionary?

Answer 1

memcached is very popular in php as a way to keep stuff in memory that can be accessed by many processes http://php.net/manual/en/book.memcached.php

a similar solution could be to use an sqlite shared memory database http://www.sqlite.org/inmemorydb.html