** Setup **

CREATE TABLE t1 (id int auto_increment primary key, val text(200));
INSERT INTO t1 values(NULL,'a');
INSERT INTO t1 values(NULL,'b');
INSERT INTO t1 values(NULL,'c');
INSERT INTO t1 values(NULL,'d');
SELECT * FROM t1 ORDER BY val;
id	val
1	a
2	b
3	c
4	d
SET SESSION query_prealloc_size  = 8192;
'#----------------------------FN_DYNVARS_137_05-----------------#'
SET GLOBAL query_prealloc_size = 8192;
SELECT @@SESSION.query_prealloc_size;
@@SESSION.query_prealloc_size
8192
Expected Value : 8192;
SET SESSION query_prealloc_size = 16384;
SELECT @@SESSION.query_prealloc_size;
@@SESSION.query_prealloc_size
8192
Expected Value : 8192;
SET SESSION query_prealloc_size = 8192;
SELECT @@SESSION.query_prealloc_size;
@@SESSION.query_prealloc_size
16384
Expected Value : 16384;
SELECT @@SESSION.query_prealloc_size;
@@SESSION.query_prealloc_size
8192
Expected Value : 8192;
SELECT @@GLOBAL.query_prealloc_size;
@@GLOBAL.query_prealloc_size
8192
Expected Value : 8192;