Can I use $_SESSION as memcache?

Every time a page is loaded I connect to the database to fetch the settings table where the basic application settings are stored. It looks uneficcient.开发者_运维知识库 I have an idea to temporary store the $settings array in $_SESSION variable. So every time the script is started it checks if $_SESSION['settings'] is empty and loads the data from DB only if it is.

My questions are:

1)Is this normal practice or there are serious pitfalls?

2)Will this speed up my application?

It looks unefficient.

it looks or it IS inefficient?

I have an idea to temporary store the $settings array in $_SESSION variable.

That's wrong idea. Sessions are for personal data, not site-wide settings. If you want to read your settings from a file - include it!

Will this speed up my application?

Is anything wrong with your application speed at the moment?

I would guess performance benefits of this would be negligible at best, and potentially harmful at worst.

Either way $_SESSION isn't really intended to be used this way, it's for data relating to a specific user, and as a general rule I try to keep it as concise as possible.

A better solution you might consider is caching the settings locally as a PHP file, it's not too hard to script something up to generate a file that creates a simple key => value array from the database that you can include. e.g.

<?php
// myconfig.php

return array(
    'mysetting' => 'value',
);

Then you can just include this file to get your config values:

<?php
// app.php

$config = include('myconfig.php');

echo $config['mysetting']; // 'value'

I would not recommend using PHP's $_SESSION as a local cache. For each visitor that comes to your site, you'll need to populate that $_SESSION variable. This is inefficient, since each visitor will get a session when they don't need. It's also difficult to manage, since changes to your settings data won't immediately be populated into the $_SESSION variable. I'd recommend something like memcached or even apc local object cache for this.