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#
# Display default value
#
select @@global.performance_schema_max_program_instances;
#
# Only global
#
select @@global.performance_schema_max_program_instances;
--error ER_INCORRECT_GLOBAL_LOCAL_VAR
select @@session.performance_schema_max_program_instances;
show global variables like 'performance_schema_max_program_instances';
show session variables like 'performance_schema_max_program_instances';
--disable_warnings
select * from performance_schema.global_variables
where variable_name='performance_schema_max_program_instances';
select * from performance_schema.session_variables
where variable_name='performance_schema_max_program_instances';
--enable_warnings
#
# Read-only
#
--error ER_INCORRECT_GLOBAL_LOCAL_VAR
set global performance_schema_max_program_instances=1;
--error ER_INCORRECT_GLOBAL_LOCAL_VAR
set session performance_schema_max_program_instances=1;
#
# Check if the value in GLOBAL Table matches value in variable
#
--disable_warnings
SELECT @@GLOBAL.performance_schema_max_program_instances = VARIABLE_VALUE
FROM performance_schema.global_variables
WHERE VARIABLE_NAME='performance_schema_max_program_instances';
--enable_warnings
select @@global.performance_schema_max_program_instances;
--disable_warnings
select * from performance_schema.global_variables
where variable_name='performance_schema_max_program_instances';
--enable_warnings
#
# Check if accessing variable with and without GLOBAL point to same variable
#
SELECT @@performance_schema_max_program_instances = @@GLOBAL.performance_schema_max_program_instances;
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