

# 2010-01-27 - Added
#

--source include/have_innodb.inc

SET @start_global_value = @@global.innodb_read_ahead_threshold;
SELECT @start_global_value;

#
# exists as global only
#
--echo Valid values are between 0 and 64
select @@global.innodb_read_ahead_threshold between 0 and 64;
select @@global.innodb_read_ahead_threshold;
--error ER_INCORRECT_GLOBAL_LOCAL_VAR
select @@session.innodb_read_ahead_threshold;
show global variables like 'innodb_read_ahead_threshold';
show session variables like 'innodb_read_ahead_threshold';
select * from information_schema.global_variables where variable_name='innodb_read_ahead_threshold';
select * from information_schema.session_variables where variable_name='innodb_read_ahead_threshold';

#
# show that it's writable
#
set global innodb_read_ahead_threshold=10;
select @@global.innodb_read_ahead_threshold;
select * from information_schema.global_variables where variable_name='innodb_read_ahead_threshold';
select * from information_schema.session_variables where variable_name='innodb_read_ahead_threshold';
--error ER_GLOBAL_VARIABLE
set session innodb_read_ahead_threshold=1;

#
# incorrect types
#
--error ER_WRONG_TYPE_FOR_VAR
set global innodb_read_ahead_threshold=1.1;
--error ER_WRONG_TYPE_FOR_VAR
set global innodb_read_ahead_threshold=1e1;
--error ER_WRONG_TYPE_FOR_VAR
set global innodb_read_ahead_threshold="foo";

set global innodb_read_ahead_threshold=-7;
select @@global.innodb_read_ahead_threshold;
select * from information_schema.global_variables where variable_name='innodb_read_ahead_threshold';
set global innodb_read_ahead_threshold=96;
select @@global.innodb_read_ahead_threshold;
select * from information_schema.global_variables where variable_name='innodb_read_ahead_threshold';

#
# min/max values
#
set global innodb_read_ahead_threshold=0;
select @@global.innodb_read_ahead_threshold;
set global innodb_read_ahead_threshold=64;
select @@global.innodb_read_ahead_threshold;

SET @@global.innodb_read_ahead_threshold = @start_global_value;
SELECT @@global.innodb_read_ahead_threshold;
