WordPress is an amazing tool for publishing a website tied into a relational database. In order to make a WordPress website perform as fast as possible, Pressable uses a number of cache types. Understanding how Pressable accelerates your website with caching will help you design better websites that perform the best for your users.
Caching
Every time a visitor lands on your WordPress website, WordPress has to fetch information from your MySQL database. If you have a lot of functionality and assets on your website, that’s a lot of information to fetch, so your load time increases.
At Pressable, there are a few types of caching occurring: page caching (Batcache, advanced-cache.php, via Memcache), database query caching (WordPress Object Cache, extended by object-cache.php via Memcache), OPCache (PHP Code), and page + static asset caching at the edge (Edge Cache, which replaces the Legacy CDN).
Page and Query Caching
Both page caching and database query caching use WordPress’ Object Cache. Page and database query caching (for queries that use the WordPress Object Cache class) are always on at Pressable. However, you can exclude certain pages from Batcache.
Edge Cache (Static Asset Caching)
Pressable provides Edge Cache across all plans, a free performance feature that allows your WordPress sites to leverage our global network of edge servers to deliver both page and static asset cache.
Edge Cache replaces the Legacy CDN by combining static asset delivery (like a traditional CDN) with full-page caching at the edge. This provides significant performance improvements, especially in terms of your site’s TTFB, by serving content directly from the closest edge server available to your visitors.
Edge Cache already acts as a CDN, adding an additional CDN (such as Jetpack CDN or another third-party provider) may introduce extra external HTTP requests and reduce performance. We recommend relying on Edge Cache alone unless you test thoroughly and confirm benefits from layering another CDN.
OPCache (PHP Code)
OPcache stores precompiled PHP code in memory, so PHP files don’t have to be compiled again every time they’re requested. This reduces server load and speeds up how quickly PHP runs.
Signature plans:
OPcache covers WordPress core files and plugins managed by Pressable (symlinked plugins).
Other plugins, themes, and custom PHP files aren’t covered. Pressable keeps managed plugins up to date automatically, so make sure any extensions or add-ons that depend on a managed plugin are kept up to date as well. If a managed plugin’s files are replaced (for example, by uploading a copy over SFTP or reinstalling it with another tool), it becomes a regular plugin and OPcache no longer covers it.
Premium plans:
OPcache for user files (your own plugins, themes, and other PHP files) can be enabled on request for Premium plans.
If you’re interested in upgrading, compare Signature and Premium plans or chat with our sales team.