1SELECT @@global.optimizer_trace_limit; 2@@global.optimizer_trace_limit 31 4SET @@global.optimizer_trace_limit=5; 5show global variables like 'optimizer_trace_limit'; 6Variable_name Value 7optimizer_trace_limit 5 8select * from information_schema.global_variables where variable_name='optimizer_trace_limit'; 9VARIABLE_NAME VARIABLE_VALUE 10OPTIMIZER_TRACE_LIMIT 5 11select @@session.optimizer_trace_limit; 12@@session.optimizer_trace_limit 131 14show session variables like 'optimizer_trace_limit'; 15Variable_name Value 16optimizer_trace_limit 1 17select * from information_schema.session_variables where variable_name='optimizer_trace_limit'; 18VARIABLE_NAME VARIABLE_VALUE 19OPTIMIZER_TRACE_LIMIT 1 20set session optimizer_trace_limit=10; 21select @@session.optimizer_trace_limit; 22@@session.optimizer_trace_limit 2310 24show session variables like 'optimizer_trace_limit'; 25Variable_name Value 26optimizer_trace_limit 10 27set session optimizer_trace_limit=0; 28select @@session.optimizer_trace_limit; 29@@session.optimizer_trace_limit 300 31show session variables like 'optimizer_trace_limit'; 32Variable_name Value 33optimizer_trace_limit 0 34set session optimizer_trace_limit=-100; 35Warnings: 36Warning 1292 Truncated incorrect optimizer_trace_limit value: '-100' 37select @@session.optimizer_trace_limit; 38@@session.optimizer_trace_limit 390 40show session variables like 'optimizer_trace_limit'; 41Variable_name Value 42optimizer_trace_limit 0 43set session optimizer_trace_limit=default; 44select @@session.optimizer_trace_limit; 45@@session.optimizer_trace_limit 465 47show session variables like 'optimizer_trace_limit'; 48Variable_name Value 49optimizer_trace_limit 5 50set global optimizer_trace_limit=default; 51select @@global.optimizer_trace_limit; 52@@global.optimizer_trace_limit 531 54show global variables like 'optimizer_trace_limit'; 55Variable_name Value 56optimizer_trace_limit 1 57set optimizer_trace_limit=1.1; 58ERROR 42000: Incorrect argument type to variable 'optimizer_trace_limit' 59set optimizer_trace_limit="foobar"; 60ERROR 42000: Incorrect argument type to variable 'optimizer_trace_limit' 61