DROP TABLE IF EXISTS t1; create table t1 ( a int primary key, b varchar(10), c varchar(10), index (b) ) engine=ndb; insert into t1 values (1,'one','one'), (2,'two','two'), (3,'three','three'); create index c on t1(c); show indexes from t1; Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment t1 0 PRIMARY 1 a A 3 NULL NULL BTREE t1 1 b 1 b A NULL NULL NULL YES BTREE t1 1 c 1 c A NULL NULL NULL YES BTREE select * from t1 where c = 'two'; a b c 2 two two alter table t1 drop index c; show indexes from t1; Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment t1 0 PRIMARY 1 a A 3 NULL NULL BTREE t1 1 b 1 b A NULL NULL NULL YES BTREE select * from t1 where c = 'two'; a b c 2 two two drop table t1; create table t3 (a int primary key) engine=ndbcluster; begin; insert into t3 values (1); alter table t3 rename t4; commit; select * from t3; ERROR 42S02: Table 'test.t3' doesn't exist select * from t4; a 1 drop table t4; show tables; Tables_in_test drop table if exists t6; create table t6 (a int primary key ,b int) engine=ndbcluster; insert into t6 values(1,12), (2,12); alter table t6 add unique key ui_t(b); ERROR 23000: Can't write, because of unique constraint, to table 't6' delete from t6; insert into t6 values(1,12), (2,12); alter table t6 add unique key ui_t(b); ERROR 23000: Can't write, because of unique constraint, to table 't6' delete from t6; drop table t6;