The default value of scale should be null not false in mssql, that is the
standard with other DBs
0 is a valid value for scale, don't change it in oracle
List of changes:
* New OOP API using PHP namespace \core\session\.
* All handlers now update the sessions table consistently.
* Experimental DB session support in Oracle.
* Full support for session file handler (filesystem locking required).
* New option for alternative session directory.
* Official memcached session handler support.
* Workaround for memcached version with non-functional gc.
* Improved security - forced session id regeneration.
* Improved compatibility with recent PHP releases.
* Fixed borked CSS during install in debug mode.
* Switched to file based sessions in new installs.
* DB session setting disappears if DB does not support sessions.
* DB session setting disappears if session handler specified in config.php.
* Fast purging of sessions used in request only.
* No legacy distinction - file, database and memcached support the same functionality.
* Session handler name included in performance info.
* Fixed user_loggedin and user_loggedout event triggering.
* Other minor bugfixing and improvements.
* Fixed database session segfault if MUC disposed before $DB.
Limitations:
* Session access time is now updated right after session start.
* Support for $CFG->sessionlockloggedinonly was removed.
* First request does not update userid in sessions table.
* The timeouts may break badly if server hosting forces PHP.ini session settings.
* The session GC is a lot slower, we do not rely on external session timeouts.
* There cannot be any hooks triggered at the session write time.
* File and memcached handlers do not support session lock acquire timeouts.
* Some low level PHP session functions can not be used directly in Moodle code.
By using a pivoting strategy, we modify the list
of params (QM and NAMED supported) into a
subquery, so the 1000 limit in Oracle (ORA-01795)
is not thrown anymore.
Sometimes the (oracle only) tweak_param_names() method was causing
placeholders having > 28 chars length to exceed the 30 chars limit
imposed by Oracle. With this commit the tweak is performed by
replacement for such long placeholders and, at the same time, the
tweak has been commented out from insert/update because it is not
necessary there (placeholders are safe column name always)
