--source include/default_optimizer_switch.inc # # 2010-01-20 OBN Added check for I_S values after variable value changed # set @@global.optimizer_switch=@@optimizer_switch; # # exists as global and session # select @@global.optimizer_switch; select @@session.optimizer_switch; show global variables like 'optimizer_switch'; show session variables like 'optimizer_switch'; select * from information_schema.global_variables where variable_name='optimizer_switch'; select * from information_schema.session_variables where variable_name='optimizer_switch'; # # show that it's writable # set global optimizer_switch=2053; set session optimizer_switch=1034; select @@global.optimizer_switch; select @@session.optimizer_switch; set global optimizer_switch="index_merge_sort_union=on"; set session optimizer_switch="index_merge=off"; select @@global.optimizer_switch; select @@session.optimizer_switch; show global variables like 'optimizer_switch'; show session variables like 'optimizer_switch'; select * from information_schema.global_variables where variable_name='optimizer_switch'; select * from information_schema.session_variables where variable_name='optimizer_switch'; set session optimizer_switch="default"; select @@session.optimizer_switch; set optimizer_switch = replace(@@optimizer_switch, '=off', '=on'); select @@optimizer_switch; # # incorrect assignments # --error ER_WRONG_TYPE_FOR_VAR set global optimizer_switch=1.1; --error ER_WRONG_TYPE_FOR_VAR set global optimizer_switch=1e1; --error ER_WRONG_VALUE_FOR_VAR set session optimizer_switch="index_merge"; --error ER_WRONG_VALUE_FOR_VAR set session optimizer_switch="foobar"; SET @@global.optimizer_switch = @save_optimizer_switch;