1select @@global.performance_schema;
2@@global.performance_schema
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4select @@session.performance_schema;
5ERROR HY000: Variable 'performance_schema' is a GLOBAL variable
6show global variables like 'performance_schema';
7Variable_name	Value
8performance_schema	ON
9show session variables like 'performance_schema';
10Variable_name	Value
11performance_schema	ON
12select * from information_schema.global_variables
13where variable_name='performance_schema';
14VARIABLE_NAME	VARIABLE_VALUE
15PERFORMANCE_SCHEMA	ON
16select * from information_schema.session_variables
17where variable_name='performance_schema';
18VARIABLE_NAME	VARIABLE_VALUE
19PERFORMANCE_SCHEMA	ON
20set global performance_schema=1;
21ERROR HY000: Variable 'performance_schema' is a read only variable
22set session performance_schema=1;
23ERROR HY000: Variable 'performance_schema' is a read only variable
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