SELECT COUNT(@@GLOBAL.innodb_purge_threads);
COUNT(@@GLOBAL.innodb_purge_threads)
1
1 Expected
SELECT COUNT(@@innodb_purge_threads);
COUNT(@@innodb_purge_threads)
1
1 Expected
SET @save_threads = @@GLOBAL.innodb_purge_threads;
SET @@GLOBAL.innodb_purge_threads=-1;
Warnings:
Warning	1292	Truncated incorrect innodb_purge_threads value: '-1'
SELECT @@GLOBAL.innodb_purge_threads;
@@GLOBAL.innodb_purge_threads
1
SET @@GLOBAL.innodb_purge_threads=0;
Warnings:
Warning	1292	Truncated incorrect innodb_purge_threads value: '0'
SELECT @@GLOBAL.innodb_purge_threads;
@@GLOBAL.innodb_purge_threads
1
SET @@GLOBAL.innodb_purge_threads=33;
Warnings:
Warning	1292	Truncated incorrect innodb_purge_threads value: '33'
SELECT @@GLOBAL.innodb_purge_threads;
@@GLOBAL.innodb_purge_threads
32
SET @@GLOBAL.innodb_purge_threads=1;
SET @@GLOBAL.innodb_purge_threads=32;
SELECT innodb_purge_threads = @@SESSION.innodb_purge_threads;
ERROR 42S22: Unknown column 'innodb_purge_threads' in 'field list'
Expected error 'Read-only variable'
SELECT @@GLOBAL.innodb_purge_threads = VARIABLE_VALUE
FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES
WHERE VARIABLE_NAME='innodb_purge_threads';
@@GLOBAL.innodb_purge_threads = VARIABLE_VALUE
1
1 Expected
SELECT COUNT(VARIABLE_VALUE)
FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES 
WHERE VARIABLE_NAME='innodb_purge_threads';
COUNT(VARIABLE_VALUE)
1
1 Expected
SELECT @@innodb_purge_threads = @@GLOBAL.innodb_purge_threads;
@@innodb_purge_threads = @@GLOBAL.innodb_purge_threads
1
1 Expected
SELECT COUNT(@@local.innodb_purge_threads);
ERROR HY000: Variable 'innodb_purge_threads' is a GLOBAL variable
Expected error 'Variable is a GLOBAL variable'
SELECT COUNT(@@SESSION.innodb_purge_threads);
ERROR HY000: Variable 'innodb_purge_threads' is a GLOBAL variable
Expected error 'Variable is a GLOBAL variable'
SELECT VARIABLE_NAME, VARIABLE_VALUE
FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES
WHERE VARIABLE_NAME = 'innodb_purge_threads';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_PURGE_THREADS	32
SET GLOBAL innodb_purge_threads = @save_threads;