Question

I’ve just made a user-content orientated website.

It is done in PHP, MySQL and jQuery’s AJAX. At the moment there is only a dozen or so submissions and already I can feel it lagging slightly when it goes to a new page (therefore running a new MySQL query)

Is it most important for me to try and optimise my MySQL queries (by prepared statements) or is it worth in looking at CDN’s (Amazon S3) and caching (much like the WordPress plugin WP Super Cache) static HTML files when there hasn’t been new content submitted.

Which route is the most beneficial, for me as a developer, to take, ie. where am I better off concentrating my efforts to speed up the site?

Answer 1

Premature optimization is the root of all evil

-Donald Knuth

Optimize when you see issues, don’t jump to conclusions and waste time optimizing what you think might be the issue.

Besides, I think you have more important things to work out on the site (like being able to cast multiple votes on the same question) before worrying about a caching layer.

Its done in PHP, MySQL and jQuery’s AJAX, at the moment there is only a dozen or so submissions and already i can feel it lagging slightly when it goes to a new page (therefore running a new mysql query)

“Can feel it lagging slightly” – Don’t feel it, know it. Run benchmarks and time your queries. Are you running queries effectively? Is the database setup with the right indexes and keys?

That being said…

CDN’s

A CDN works great for serving static content. CSS, JavaScript, images, etc. This can speed up the loading of the page by minimizing the time it takes to request all the resources. It will not fix bad query practice.

Content Caching

The easiest way to implement content caching is with something like Varnish. Basically sits in front of your site and re-serves content that hasn’t been updated. Minimally intrusive and easy to setup while being amazingly effective.

Database

Is it most important for me to try and optimise my MySQL queries (by prepared statements)

Why the hell aren’t you already using prepared statements? If you’re doing raw SQL queries always use prepared statements unless you absolutely trust the content in the queries. Given a user content based site I don’t think you can safely say that. If you notice query times running high then take a look at the database schema, the queries you are running per-page, and the amount of content you have. With a few dozen entries you should not be noticing any issue even with the worst queries.