Version Tokens mysql>  SELECT version_tokens_set(’tok1=value1;tok2=value2’); +-----------------------------------------------+ | version_tokens_set(’tok1=value1;tok2=value2’) | +-----------------------------------------------+ | 2 version tokens set. | +-----------------------------------------------+ • version_tokens_show() • version_tokens_lock_exclusive( token_name [,  token_name ] ...,  timeout ) • version_tokens_lock_shared( token_name [,  token_name ] ...,  timeout ) • version_tokens_unlock() •The return value is nonzero for success. Otherwise, an error occurs. •Token names are strings. 1107 The locking functions share these characteristics: Releases all locks that were acquired within the current session using version_tokens_lock_exclusive()  and  version_tokens_lock_shared() . Acquires shared locks on one or more version tokens, specified by name as strings, timing out with an error if the locks are not acquired within the given timeout value. Acquires exclusive locks on one or more version tokens, specified by name as strings, timing out with an error if the locks are not acquired within the given timeout value. The following functions permit version tokens to be locked and unlocked: Returns the server’s list of version tokens as a binary string containing a semicolon-separated list of name = value  pairs. mysql>  SELECT version_tokens_show(); +--------------------------+ | version_tokens_show() | +--------------------------+ | tok2=value2;tok1=value1; | +--------------------------+ mysql>  SELECT version_tokens_lock_exclusive(’lock1’, ’lock2’, 10); +-----------------------------------------------------+ | version_tokens_lock_exclusive(’lock1’, ’lock2’, 10) | +-----------------------------------------------------+ | 1 | +-----------------------------------------------------+ mysql>  SELECT version_tokens_lock_shared(’lock1’, ’lock2’, 10); +--------------------------------------------------+ | version_tokens_lock_shared(’lock1’, ’lock2’, 10) | +--------------------------------------------------+ | 1 | +--------------------------------------------------+ mysql>  SELECT version_tokens_unlock(); +-------------------------+ | version_tokens_unlock() | +-------------------------+ | 1 | +-------------------------+