Session support is enabled in PHP by default. If you would
not like to build your PHP with session support, you should
specify the --disable-session
option to configure. To use shared memory allocation (mm) for session
storage configure PHP --with-mm[=DIR] .
The Windows version of PHP has built-in
support for this extension. You do not need to load any additional
extensions in order to use these functions.
By default, all data related to a particular session will be stored in
a file in the directory specified by the session.save_path INI option.
A file for each session (regardless of if any data is associated with
that session) will be created. This is due to the fact that a session
is opened (a file is created) but no data is even written to that file.
Note that this behavior is a side-effect of the limitations of working
with the file system and it is possible that a custom session handler
(such as one which uses a database) does not keep track of sessions
which store no data.