# Displaying default value
SELECT COUNT(@@GLOBAL.have_statement_timeout);
COUNT(@@GLOBAL.have_statement_timeout)
1
1 Expected
# Check if Value can set
SET @@GLOBAL.have_statement_timeout=1;
ERROR HY000: Variable 'have_statement_timeout' is a read only variable
Expected error 'Read only variable'
SELECT COUNT(@@GLOBAL.have_statement_timeout);
COUNT(@@GLOBAL.have_statement_timeout)
1
1 Expected
# Check if the value in GLOBAL Table matches value in variable
SELECT @@GLOBAL.have_statement_timeout = VARIABLE_VALUE
FROM performance_schema.global_variables
WHERE VARIABLE_NAME='have_statement_timeout';
@@GLOBAL.have_statement_timeout = VARIABLE_VALUE
1
1 Expected
SELECT COUNT(@@GLOBAL.have_statement_timeout);
COUNT(@@GLOBAL.have_statement_timeout)
1
1 Expected
SELECT COUNT(VARIABLE_VALUE)
FROM performance_schema.global_variables
WHERE VARIABLE_NAME='have_statement_timeout';
COUNT(VARIABLE_VALUE)
1
1 Expected
# Check if accessing variable with and without GLOBAL point to same variable
SELECT @@have_statement_timeout = @@GLOBAL.have_statement_timeout;
@@have_statement_timeout = @@GLOBAL.have_statement_timeout
1
1 Expected
# Check if have_statement_timeout can be accessed with and without @@ sign
SELECT COUNT(@@have_statement_timeout);
COUNT(@@have_statement_timeout)
1
1 Expected
SELECT COUNT(@@local.have_statement_timeout);
ERROR HY000: Variable 'have_statement_timeout' is a GLOBAL variable
Expected error 'Variable is a GLOBAL variable'
SELECT COUNT(@@SESSION.have_statement_timeout);
ERROR HY000: Variable 'have_statement_timeout' is a GLOBAL variable
Expected error 'Variable is a GLOBAL variable'
SELECT COUNT(@@GLOBAL.have_statement_timeout);
COUNT(@@GLOBAL.have_statement_timeout)
1
1 Expected
SELECT have_statement_timeout = @@SESSION.have_statement_timeout;
ERROR 42S22: Unknown column 'have_statement_timeout' in 'field list'
Expected error 'Readonly variable'