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DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (
a varchar(32) collate utf8_bin NOT NULL,
b varchar(32) collate utf8_bin NOT NULL );
INSERT INTO t1 VALUES
('AAAAAAAAAA','AAAAAAAAAA'), ('AAAAAAAAAB','AAAAAAAAAB '),
('AAAAAAAAAB','AAAAAAAAAB'), ('AAAAAAAAAC','AAAAAAAAAC'),
('AAAAAAAAAD','AAAAAAAAAD'), ('AAAAAAAAAE','AAAAAAAAAE'),
('AAAAAAAAAF','AAAAAAAAAF'), ('AAAAAAAAAG','AAAAAAAAAG'),
('AAAAAAAAAH','AAAAAAAAAH'), ('AAAAAAAAAI','AAAAAAAAAI'),
('AAAAAAAAAJ','AAAAAAAAAJ'), ('AAAAAAAAAK','AAAAAAAAAK');
set tmp_table_size=1024;
SELECT MAX(a) FROM t1 GROUP BY a,b;
MAX(a)
AAAAAAAAAA
AAAAAAAAAB
AAAAAAAAAC
AAAAAAAAAD
AAAAAAAAAE
AAAAAAAAAF
AAAAAAAAAG
AAAAAAAAAH
AAAAAAAAAI
AAAAAAAAAJ
AAAAAAAAAK
set tmp_table_size=default;
DROP TABLE t1;
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