Caching - Can Someone Please Explain?

[AA15]

Hi Invision Community. I was hoping is somebody could please explain the caching system in Invision?

In the ACP it says...

Quote

The data storage method is used by various systems to save arbitrary data. If caching is enabled, using the MySQL Database provides the best performance for most environments, otherwise using the File System is usually best.

1. For file system, is that were Invision saves a static HTML page to the disk and serves that to users? Why does Invision say MySQL is better when hitting a database is more intensive than hitting a static HTML file?

 

2. Also what is the difference between "Data Storage Method" and "Caching Method"? I've had a WordPress site in the past and often my CPU usage would spike to the point where the server would crash (thankfully W3TotalCache created static HTML files for caching purposes and that stopped that issue). Which caching method in Invision uses less server resources?

Edited May 27, 2020 by AA15

[bfarber]

Data storage aren't cached HTML pages - it's largely smaller bits of data that get reused, so they're compiled and stored to save processing on future page loads. We find that MySQL generally performs better than storing the caches on disk, but you can try both and see which is better in your environment.

Caching relates to taking those compiled bits of data and storing them in a proper cache handler, such as memcache or redis.

We recommend using redis if it is available.