Holographic Extreme Cache vs SQLite Object Cache

Holographic Extreme Cache is a simple, yet powerful, static page caching plugin with safe defaults. It includes static HTML page caching, smart cache clearing, safe WooCommerce exclusions, debug response headers, a basic preload system, a cache health check, safe HTML minification, WordPress emoji disabling, browser cache helper rules, new-upload WebP conversion where supported, a homepage speed test, cache diagnostics and an uninstall cleanup option. Caching is not enabled automatically on activation. Open Holo-Cache in the WordPress admin area and use the Setup tab or enable caching manually. Features Static HTML page caching. PHP fallback cache delivery. advanced-cache.php drop-in support. Optional Apache rewrite helper rules. Manual clear cache button. Admin bar cache clearing. Automatic cache clearing when content changes. Basic smart purge for posts, pages, archives, taxonomy archives, authors and homepage. Cache lifetime control. Basic preload for homepage, recent posts and recent pages. Combined cache and preload controls for simpler setup. Safe default exclusions. WooCommerce cart, checkout and account exclusions. Logged-in user bypass by default. POST, AJAX, REST, preview and unsafe query string bypass. Cache size and cached page count. Last purge and last preload time. Basic cache health check. Other caching plugin conflict detection. Debug response headers. Strong cached HTML and inline CSS minification. Disable WordPress emoji files option. Browser cache helper. New-upload WebP conversion for JPEG and PNG images where the server supports it. Safe picture/source markup for generated WebP files, with original images kept as fallbacks. Clear server requirement messaging when WebP conversion is unavailable. Gzip and Brotli detection. Setup tab with one-click WP_CACHE handling where wp-config.php is writable. Setup checklist for the main cache, speed test, preload, health and optional image steps. Simple homepage speed test for cache-off and cache-on comparison with expandable diagnostics. Safe and Balanced modes. Optional uninstall cleanup. Privacy Holographic Extreme Cache does not collect analytics, does not track visitors and does not send site data to a third-party service. The plugin stores cache files, configuration helper files and optional log files inside its own folder under the WordPress uploads directory. Logging is off by default. Uninstall The plugin can remove its settings, cache files, configuration files, log files and scheduled events on uninstall if the uninstall cleanup option is enabled before uninstalling. If uninstall cleanup is not enabled, settings and generated files are left in place so the site owner can remove or inspect them manually.

A persistent object cache helps your site perform well. This one uses the widely available SQLite3 extension, and optionally the igbinary and APCu extensions to php. Many hosting services offer those extensions, and they are easy to install on a server you control. What is this about? It’s about making your site’s web server perform better. An object cache does that by reducing the workload on your MariaDB or MySQL database. This is not a page cache; these persistent objects go into a different kind of cache. These objects aren’t chunks of web pages ready for people to view in their browsers, they are data objects for use by the WordPress software. Caches are ubiquitous in computing, and WordPress has its own caching subsystem. Caches contain short-term copies of the results of expensive database lookups or computations, and allow software to use the copy rather than repeating the expensive operation. This plugin (like other object-caching plugins) extends WordPress’s caching subsystem to save those short-term copies from page view to page view. WordPress’s cache happens to be a memoization cache. Without a persistent object cache, every WordPress page view must use your MariaDB or MySQL database server to retrieve everything about your site. When a user requests a page, WordPress starts from scratch and loads everything it needs from your database server. Only then can it deliver content to your user. With a persistent object cache, WordPress immediately loads much of the information it needs. This lightens the load on your database server and delivers content to your users faster. Who should use this? If your site runs on a single web server machine, and that server provides the SQLite3 and igbinary extensions to php, this plugin will almost certainly make your site work faster. And if that server provides the APCu extension, this plugin uses it too. Some hosting providers offer redis cache servers. If your provider offers redis, it may be a good choice. You can use it via the Redis Object Cache plugin. Sites using redis have one SQL database and another non-SQL storage server: redis. Other hosting providers offer memcached, which has the Memcached Object Cache plugin. And some large multipurpose cache plugins, such as the LiteSpeed Cache, also offer object caching based on one of those cache server software packages. The cache-server approach to object caching comes into its own when you have multiple load-balanced web server machines handling your site. SQLite doesn’t work correctly in a multiple-web-server environment. But, for single-server site configurations, SQLite, possibly assisted by APCu, performs well. And the vast majority of sites are single-server. APCu APCu is an in-memory storage medium. It lets php programs, like WordPress, store data in shared memory so it’s very fast to retrieve when needed. If APCu is available on your host server, you can configure this plugin to use it. It reduces the typical cache lookup time to one-fifth or less of the SQLite lookup time, which is itself a few tens of microseconds. Performance counts, especially on busy web sites. Please look at Installation to learn how to configure this plugin to use APCu. The plugin works fast without it, and faster with it. WP-CLI: Even if APCu is in use, caching with SQLite is necessary when your web site uses WP-CLI, because WP-CLI programs do not have access to the APCu cache. This plugin writes all cached data both to APCu and to SQLite and makes sure the two are synchronized. WP-CLI You can control this plugin via WP-CLI once you activate it. Please type this command into your shell for details. wp help sqlite-object-cache Credits Thanks to Till Krüss. His Redis Object Cache plugin serves as a model for this one. And thanks to Ari Stathopoulos and Jonny Harris for reviewing this. Props to Matt Jones for finding and fixing a bug that appeared on a heavily loaded system. Thanks to Massimo Villa for testing help, and to nickchomey for a comprehensive code review. All defects are, of course, entirely the author’s responsibility. And thanks to Jetbrains for the use of their software development tools, especially PhpStorm. It’s hard to imagine how a plugin like this one could be developed without PhpStorm’s tools for exploring epic code bases like WordPress’s. How can I learn more about making my WordPress site more efficient? We offer several plugins to help with your site’s database efficiency. You can read about them here.