1SET @start_global_value = @@global.thread_cache_size; 2SELECT @start_global_value; 3@start_global_value 49 5select @@global.thread_cache_size; 6@@global.thread_cache_size 79 8select @@session.thread_cache_size; 9ERROR HY000: Variable 'thread_cache_size' is a GLOBAL variable 10show global variables like 'thread_cache_size'; 11Variable_name Value 12thread_cache_size 9 13show session variables like 'thread_cache_size'; 14Variable_name Value 15thread_cache_size 9 16select * from information_schema.global_variables where variable_name='thread_cache_size'; 17VARIABLE_NAME VARIABLE_VALUE 18THREAD_CACHE_SIZE 9 19select * from information_schema.session_variables where variable_name='thread_cache_size'; 20VARIABLE_NAME VARIABLE_VALUE 21THREAD_CACHE_SIZE 9 22set global thread_cache_size=1; 23select @@global.thread_cache_size; 24@@global.thread_cache_size 251 26select * from information_schema.global_variables where variable_name='thread_cache_size'; 27VARIABLE_NAME VARIABLE_VALUE 28THREAD_CACHE_SIZE 1 29select * from information_schema.session_variables where variable_name='thread_cache_size'; 30VARIABLE_NAME VARIABLE_VALUE 31THREAD_CACHE_SIZE 1 32set session thread_cache_size=1; 33ERROR HY000: Variable 'thread_cache_size' is a GLOBAL variable and should be set with SET GLOBAL 34SET @@global.thread_cache_size = DEFAULT; 35SELECT @@global.thread_cache_size ; 36@@global.thread_cache_size 379 38SET @@global.thread_cache_size=-1; 39Warnings: 40Warning 1292 Truncated incorrect thread_cache_size value: '-1' 41SELECT @@global.thread_cache_size; 42@@global.thread_cache_size 430 44SET @@global.thread_cache_size=16385; 45Warnings: 46Warning 1292 Truncated incorrect thread_cache_size value: '16385' 47SELECT @@global.thread_cache_size; 48@@global.thread_cache_size 4916384 50SET @@global.thread_cache_size=163856; 51Warnings: 52Warning 1292 Truncated incorrect thread_cache_size value: '163856' 53SELECT @@global.thread_cache_size; 54@@global.thread_cache_size 5516384 56SET @@global.thread_cache_size=-1635; 57Warnings: 58Warning 1292 Truncated incorrect thread_cache_size value: '-1635' 59SELECT @@global.thread_cache_size; 60@@global.thread_cache_size 610 62SET @@global.thread_cache_size=' '; 63ERROR 42000: Incorrect argument type to variable 'thread_cache_size' 64SELECT @@global.thread_cache_size; 65@@global.thread_cache_size 660 67SET @@global.thread_cache_size=255.2; 68ERROR 42000: Incorrect argument type to variable 'thread_cache_size' 69SELECT @@global.thread_cache_size; 70@@global.thread_cache_size 710 72set global thread_cache_size=1.1; 73ERROR 42000: Incorrect argument type to variable 'thread_cache_size' 74set global thread_cache_size=1e1; 75ERROR 42000: Incorrect argument type to variable 'thread_cache_size' 76set global thread_cache_size="foo"; 77ERROR 42000: Incorrect argument type to variable 'thread_cache_size' 78set global thread_cache_size=0; 79select @@global.thread_cache_size; 80@@global.thread_cache_size 810 82set global thread_cache_size=cast(-1 as unsigned int); 83Warnings: 84Warning 1292 Truncated incorrect thread_cache_size value: '18446744073709551615' 85select @@global.thread_cache_size; 86@@global.thread_cache_size 8716384 88SET @@global.thread_cache_size = @start_global_value; 89SELECT @@global.thread_cache_size; 90@@global.thread_cache_size 919 92