What's quicker; including another file or querying a MySQL database in PHP?

Question

In PHP, which is quicker; using include(\'somefile.php\') or querying a MySQL database with a simple SELECT query to get the same information?

Answer 1

If you use a PHP bytecode cache like APC or Xcache, including the file is likely to be faster. If you're using PHP and you want performance, a bytecode cache is absolutely a requirement.

It sounds like you're considering keeping static data around in a PHP script that you include, to avoid hitting the database. You're basically doing a rudimentary cache. This can work okay, as long as you have some way to refresh that file if/when the data does change. You might also look want to learn about the MySQL Query Cache to make SQL queries against static data faster. Or Memcached for keeping static data in memory.