1SET @start_global_value = @@global.old_alter_table; 2SELECT @start_global_value; 3@start_global_value 4DEFAULT 5select @@global.old_alter_table; 6@@global.old_alter_table 7DEFAULT 8select @@session.old_alter_table; 9@@session.old_alter_table 10DEFAULT 11show global variables like 'old_alter_table'; 12Variable_name Value 13old_alter_table DEFAULT 14show session variables like 'old_alter_table'; 15Variable_name Value 16old_alter_table DEFAULT 17select * from information_schema.global_variables where variable_name='old_alter_table'; 18VARIABLE_NAME VARIABLE_VALUE 19OLD_ALTER_TABLE DEFAULT 20select * from information_schema.session_variables where variable_name='old_alter_table'; 21VARIABLE_NAME VARIABLE_VALUE 22OLD_ALTER_TABLE DEFAULT 23set global old_alter_table=1; 24set session old_alter_table=1; 25select @@global.old_alter_table; 26@@global.old_alter_table 27COPY 28select @@session.old_alter_table; 29@@session.old_alter_table 30COPY 31show global variables like 'old_alter_table'; 32Variable_name Value 33old_alter_table COPY 34show session variables like 'old_alter_table'; 35Variable_name Value 36old_alter_table COPY 37select * from information_schema.global_variables where variable_name='old_alter_table'; 38VARIABLE_NAME VARIABLE_VALUE 39OLD_ALTER_TABLE COPY 40select * from information_schema.session_variables where variable_name='old_alter_table'; 41VARIABLE_NAME VARIABLE_VALUE 42OLD_ALTER_TABLE COPY 43set global old_alter_table=2; 44set session old_alter_table=2; 45select @@global.old_alter_table; 46@@global.old_alter_table 47INPLACE 48select @@session.old_alter_table; 49@@session.old_alter_table 50INPLACE 51show global variables like 'old_alter_table'; 52Variable_name Value 53old_alter_table INPLACE 54show session variables like 'old_alter_table'; 55Variable_name Value 56old_alter_table INPLACE 57select * from information_schema.global_variables where variable_name='old_alter_table'; 58VARIABLE_NAME VARIABLE_VALUE 59OLD_ALTER_TABLE INPLACE 60select * from information_schema.session_variables where variable_name='old_alter_table'; 61VARIABLE_NAME VARIABLE_VALUE 62OLD_ALTER_TABLE INPLACE 63set global old_alter_table=3; 64set session old_alter_table=3; 65select @@global.old_alter_table; 66@@global.old_alter_table 67NOCOPY 68select @@session.old_alter_table; 69@@session.old_alter_table 70NOCOPY 71show global variables like 'old_alter_table'; 72Variable_name Value 73old_alter_table NOCOPY 74show session variables like 'old_alter_table'; 75Variable_name Value 76old_alter_table NOCOPY 77select * from information_schema.global_variables where variable_name='old_alter_table'; 78VARIABLE_NAME VARIABLE_VALUE 79OLD_ALTER_TABLE NOCOPY 80select * from information_schema.session_variables where variable_name='old_alter_table'; 81VARIABLE_NAME VARIABLE_VALUE 82OLD_ALTER_TABLE NOCOPY 83set global old_alter_table=4; 84set session old_alter_table=4; 85select @@global.old_alter_table; 86@@global.old_alter_table 87INSTANT 88select @@session.old_alter_table; 89@@session.old_alter_table 90INSTANT 91show global variables like 'old_alter_table'; 92Variable_name Value 93old_alter_table INSTANT 94show session variables like 'old_alter_table'; 95Variable_name Value 96old_alter_table INSTANT 97select * from information_schema.global_variables where variable_name='old_alter_table'; 98VARIABLE_NAME VARIABLE_VALUE 99OLD_ALTER_TABLE INSTANT 100select * from information_schema.session_variables where variable_name='old_alter_table'; 101VARIABLE_NAME VARIABLE_VALUE 102OLD_ALTER_TABLE INSTANT 103set global old_alter_table=1.1; 104ERROR 42000: Incorrect argument type to variable 'old_alter_table' 105set global old_alter_table=1e1; 106ERROR 42000: Incorrect argument type to variable 'old_alter_table' 107set global old_alter_table="foo"; 108ERROR 42000: Variable 'old_alter_table' can't be set to the value of 'foo' 109SET @@global.old_alter_table = @start_global_value; 110SELECT @@global.old_alter_table; 111@@global.old_alter_table 112DEFAULT 113