On a shared host we have some typo3-based sites where we use indexed search.
The table index_rel grows very fast, having over 6.000.000 entries. Even a simple search takes over 30 seconds to complete.
I searched for an elegant solution with very little success.
Here is a brute force solution: a ruby-script that search for databases that have a index_rel-table, truncates the “indexed search tables” if they reach a given size. The table will be automatically refilled every time a page is accessed, even by bots….
The script truncates the “cache tables” also, the “indexed search tables” will not be rebuild if only the cache for a given page is returned by a request.
If you do not have a single user that has access to all the databases, you should configure usernames/passwords per database.