WordPress: Persistent object cache

Self-tutoring about WordPress: the tutor offers an explanation of the term “persistent object cache.”

The following is according to my understanding.

One might see a recommendation, in the Site Health tool of a WordPress site, to use a persistent object cache. Yet, what is that, and why might it be useful?

A WordPress site is its file structure and its database: virtually every page rendered thereby begins as a request for “these files” along with a query to its database for “that content.” The page one sees rendered is the combination of instructions executed from those particular files, together with the specific content retrieved from the database. Usually, it all loads so quickly that one wouldn’t realize it’s many separate parts. Nonetheless, in many WordPress installations, the header, the footer, and the side menu of a page are all stored as separate files, and will load around whatever content from the database the visitor happened to ask for this time.

The object, in such a case, is the collection of files and content that the server reads, follows, and sends to the visitor’s browser. Moreover, each member of the collection could also be seen as an object – the contents of one file, for instance. A persistent object cache can store those objects. When the next request arrives, the server will check the persistent object cache first; any resources it can find there don’t have to be hunted from the file structure or from the database. The cache is set up so it’s much quicker to search and retrieve from than the background file system or database.

Source:

cloudways.com

wordpress.org/support