php - What are the common practices of storing large user data from their inputs that will be shared with others through a search query?

I would like to know how applications such as Quizlet or Studystack manage all their user card sets that potentially could be very large. If you store the data in a database such as MySQL, wouldn't the large amounts of data eventually make the database slower? And if you are trying to search through the database for a specific key word such as "biology" in which you need to return relevant data to be incorporated into an html page for the user when they click a link, wouldn't that prove to be difficult? Could somebody explain how it works and proper techniques? Thanks.

Solution:

If you are interersted by Xuggler I maintain a fork and you can use these binaries https://cloudsmith.io/~olivier-ayache/repos/first-repo/packages/detail/maven/xuggle-xuggler-server-all/5.7.0-20210205.154804-12/a=noarch;xg=xuggle/

Here is my fork https://github.com/olivierayache/xuggle-xuggler