[eluser]kevinprince[/eluser]
Which one is better depends on what your doing.
File System caching will be faster but queries in RAM are faster. The difference is you can cheapely have 1gb of Hard Drive space on a shared host but 1gb ram isnt. On a low traffic site no real speed different.
CI cache like memcached requires you to delete the caches to display new results were as MYSQL manages the RAM cache and erases it if the table is erased.
It really depends on your server setup, and your application. A Twitter like application would make more sense to use RAM based caching because you want changes to appear in the site instantly but for a content site like BBC file based is fine.
Alternative to this would be to included a command to erase the cache when you update the table.
Hope this helps, if you let us know what your building might be able to advise you better.
