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SET DEFAULT_STORAGE_ENGINE = 'tokudb';
DROP TABLE IF EXISTS t1,t2;
#
# Bug#50843: Filesort used instead of clustered index led to
# performance degradation.
#
create table t1(f1 int not null primary key, f2 int);
create table t2(f1 int not null, key (f1));
insert into t1 values (1,1),(2,2),(3,3);
insert into t2 values (1),(2),(3);
explain select t1.* from t1 left join t2 using(f1) group by t1.f1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL NA Using temporary; Using filesort
1 SIMPLE t2 ref f1 f1 4 test.t1.f1 NA Using index
alter table t1 drop primary key;
alter table t1 add index (f1) clustering=yes;
explain select t1.* from t1 left join t2 using(f1) group by t1.f1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL f1 4 NULL NA Using index
1 SIMPLE t2 ref f1 f1 4 test.t1.f1 NA Using index
drop table t1,t2;
#
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