1select @@global.pseudo_thread_id; 2ERROR HY000: Variable 'pseudo_thread_id' is a SESSION variable 3select @@session.pseudo_thread_id between 1 and 10000; 4@@session.pseudo_thread_id between 1 and 10000 51 6should be empty 7show global variables like 'pseudo_thread_id'; 8Variable_name Value 9show session variables like 'pseudo_thread_id'; 10Variable_name Value 11pseudo_thread_id # 12should be empty 13select * from information_schema.global_variables where variable_name='pseudo_thread_id'; 14VARIABLE_NAME VARIABLE_VALUE 15select @@session.pseudo_thread_id = variable_value from information_schema.session_variables where variable_name='pseudo_thread_id'; 16@@session.pseudo_thread_id = variable_value 171 18set session pseudo_thread_id=42; 19select @@session.pseudo_thread_id; 20@@session.pseudo_thread_id 2142 22select * from information_schema.global_variables where variable_name='pseudo_thread_id'; 23VARIABLE_NAME VARIABLE_VALUE 24select variable_value from information_schema.session_variables where variable_name='pseudo_thread_id'; 25variable_value 2642 27set global pseudo_thread_id=1; 28ERROR HY000: Variable 'pseudo_thread_id' is a SESSION variable and can't be used with SET GLOBAL 29set session pseudo_thread_id=1.1; 30ERROR 42000: Incorrect argument type to variable 'pseudo_thread_id' 31set session pseudo_thread_id=1e1; 32ERROR 42000: Incorrect argument type to variable 'pseudo_thread_id' 33set session pseudo_thread_id="foo"; 34ERROR 42000: Incorrect argument type to variable 'pseudo_thread_id' 35