SET @start_value = @@global.delay_key_write;
SELECT @start_value;
@start_value
ON
'#--------------------FN_DYNVARS_023_01------------------------#'
SET @@global.delay_key_write = OFF;
SET @@global.delay_key_write = DEFAULT;
SELECT @@global.delay_key_write;
@@global.delay_key_write
ON
'#---------------------FN_DYNVARS_023_02-------------------------#'
SET @@global.delay_key_write = NULL;
ERROR 42000: Variable 'delay_key_write' can't be set to the value of 'NULL'
'#--------------------FN_DYNVARS_023_03------------------------#'
SET @@global.delay_key_write = ON;
SELECT @@global.delay_key_write;
@@global.delay_key_write
ON
SET @@global.delay_key_write = OFF;
SELECT @@global.delay_key_write;
@@global.delay_key_write
OFF
SET @@global.delay_key_write = ALL;
SELECT @@global.delay_key_write;
@@global.delay_key_write
ALL
'#--------------------FN_DYNVARS_023_04-------------------------#'
SET @@global.delay_key_write = 3;
ERROR 42000: Variable 'delay_key_write' can't be set to the value of '3'
SET @@global.delay_key_write = -1;
ERROR 42000: Variable 'delay_key_write' can't be set to the value of '-1'
SET @@global.delay_key_write = TRU;
ERROR 42000: Variable 'delay_key_write' can't be set to the value of 'TRU'
SET @@global.delay_key_write = ERROR;
ERROR 42000: Variable 'delay_key_write' can't be set to the value of 'ERROR'
SET @@global.delay_key_write = FALSE0;
ERROR 42000: Variable 'delay_key_write' can't be set to the value of 'FALSE0'
SET @@global.delay_key_write = ONN;
ERROR 42000: Variable 'delay_key_write' can't be set to the value of 'ONN'
SET @@global.delay_key_write = OF;
ERROR 42000: Variable 'delay_key_write' can't be set to the value of 'OF'
SET @@global.delay_key_write = ' ';
ERROR 42000: Variable 'delay_key_write' can't be set to the value of ' '
SET @@global.delay_key_write = "";
ERROR 42000: Variable 'delay_key_write' can't be set to the value of ''
'#-------------------FN_DYNVARS_023_05----------------------------#'
SET @@delay_key_write = 0;
ERROR HY000: Variable 'delay_key_write' is a GLOBAL variable and should be set with SET GLOBAL
SELECT @@session.delay_key_write;
ERROR HY000: Variable 'delay_key_write' is a GLOBAL variable
'#----------------------FN_DYNVARS_023_06------------------------#'
SELECT @@delay_key_write = VARIABLE_VALUE 
FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES 
WHERE VARIABLE_NAME='delay_key_write';
@@delay_key_write = VARIABLE_VALUE
1
'#---------------------FN_DYNVARS_023_07-------------------------#'
SET @@global.delay_key_write = 0;
SELECT @@global.delay_key_write;
@@global.delay_key_write
OFF
SET @@global.delay_key_write = 1;
SELECT @@global.delay_key_write;
@@global.delay_key_write
ON
SET @@global.delay_key_write = 2;
SELECT @@global.delay_key_write;
@@global.delay_key_write
ALL
'#---------------------FN_DYNVARS_023_08----------------------#'
SET @@global.delay_key_write = TRUE;
SELECT @@global.delay_key_write;
@@global.delay_key_write
ON
SET @@global.delay_key_write = FALSE;
SELECT @@global.delay_key_write;
@@global.delay_key_write
OFF
'#---------------------FN_DYNVARS_023_09----------------------#'
SET delay_key_write = ON;
ERROR HY000: Variable 'delay_key_write' is a GLOBAL variable and should be set with SET GLOBAL
SELECT @@delay_key_write;
@@delay_key_write
OFF
SET GLOBAL delay_key_write = OFF;
SELECT @@global.delay_key_write;
@@global.delay_key_write
OFF
SET @@global.delay_key_write = @start_value;
SELECT @@global.delay_key_write;
@@global.delay_key_write
ON