[quote name='Struck' timestamp='1330137309' post='132038']
Go to your CS-Cart Admin panel, then click Administration>Database>PHP Information
Then look towards the bottom of your phpinfo page to see if there is a block of information labeled SQLITE3, if there is not, then either install this module or ask your hosting provider for assistance as this is needed for the SQLITE cache method to work for you.
[/quote]
It's not there, but it wasn't there on my old server either and sqlite cache worked there. I can see the sqlite lines in my php.ini I believe. Says pdo sqlite, but in whm is says sqlite3. Could it be anything related to suPhp? php5? mod_security? these are all different from my old server where it was working.
The sqlite caching in 2.2.4 will work with either sqlite3 or PDO sqlite.
Sqlite3 is an improved version and will be faster with less contention.
Hah… Has anyone ever tried enabling the QUICK SEARCH add-on in CS-Cart, running an index, etc?
With just a couple thousand products, your database grows EXPONENTIALLY!
And even if you disable the QUICK SEARCH add-on, the database does not reduce in size! The additional 10 MB, perhaps more, remains there!
I’ve never had the nerve to try and drop the table Quick Search, but this is certainly a concern for speed and performance increases… I don’t know how it could be done when it seems CS-Cart add-ons do not clean up after themselves with any maintenance functions and routines.
Oh well! 
which one is the most recommended actually to 4.2.1?
What is the “Quick Search” addon you are referring to?
Disabling an addon doesn't change anyting other than it's availability. If you Uninstall an addon, it should remove DB tables and template hooks.
[quote name='tbirnseth' timestamp='1408046153' post='189590']What is the “Quick Search” addon you are referring to?[/quote]
Add on that used to be in default CSC but is no longer. However, Alt-Team has made it compatible for current version.
Basically the add on indexes (by choice I believe but probably everything by default) Product name, Description, Short description, Search words whereas you will easily double your data base size if all are included in the indexing.
Okay, the OP was talking about cs-cart not cleaning up after themselves but also talked about disabling versus uninstallling.
Creating an index takes space and if it's done correctly utilizes the db effectively to make things faster. The space is not a factor if it's indexed correctly and prevents full table scans.