Is a file based cache as fast as a file based session handler in PHP?

Question

I am curious would a file based cache be just as fast as a file based session handler in PHP?

Answer 1

I suppose a couple of differences could come from these points :

• file-based cache, contraty to session-based one, could be shared by several used
• session are not necessarily stored in files (you could use a database, memcached, ... )
• sessions are read automatically by PHP each time you are calling session_start(), and written back to disk at the end of the script -- which can be more often than if you are dealing with the cache's files yourself, reading/writting them only when necessary
• Data written to / read from session are serialized -- for files, if you are writting only string, there is no need to serialize (and you are the only one who can know if serialization is needed or not)
• you can delete a file from cache easily -- you cannot delete data from the session of another user than the current one

Another things :

• Sessions are generally used to store small pieces of data
• Sessions should be used to store only data specific to one used