When I use the search function on my website, it shows results with old content. I tried to clear all caches but it doesn't solve the issue.
I am not sure if I should truncate some tables in the DB and how safe this is.
By the way I don't have any "indexed search" option in the Backend under "Info".
Which TYPO3 Version are you using? With TYPO3 8.7 (not sure if also with 7.6) the module moved to an own one called "Indexing".
Anyway you shouldn't get any problem truncating the indexed_search tables in the DB as they get shipped without data when you install indexed_search.
To be sure, just make a backup of the tables.
