… on PHP level, which means they also will be serialized for single user on database level. If you change to store PHP sessions… request SELECT RELEASE_LOCK(”) where session_id is current session identifier. Note – setting this external lock on session name should be done before session data is…

Dmitry, SELECT * FROM SESSIONS WHERE SESSION_ID=”aabbcc” FOUR UPDATE; will only lock that row if it is primary key. So you should… on the same session as you would have processes waiting on the same file in case of file based PHP sessions. If you have high concurrency within single session it of course does not work well but in this case plain MySQL sessions…

“PHP will lock session file for whole script execution duration” If you know that the script will not need to write anything into the session any more, it is possible to call session_write_close(). Reading is still possible though.

… my experience with an application design problem – when PHP issues locking select for the session right at the beginning and releases (if finishes… do the same, the situation I described occurs… then the session purgers kicks in, and I get called

… which explicitly rolls back any pending transactions and writes the session data to db. It works without any issues, I wasn… aware of the concurrent session use issue though. I use a session table with a varchar primary key that PHP uses as the… me to execute 2 queries with LOCK FOR UPDATE to make use for row level locking though? First SELECT id… WHERE name…