use ndbinfo;
Create a view which should be deterministic
and exclude runtime specifics
create view ndbinfo.ordered_locks as
select mode, state, detail, op, 
if(ifnull(waiting_for, 0xffffff00) = 0xffffff00, 0, 1) as waiting 
from ndbinfo.cluster_locks
order by
node_id, block_instance, tableid, fragmentid, rowid, transid;
create table test.t1 (a int primary key, b int, c int, key(c)) engine=ndb;
insert into test.t1 values (1,1,1), (2,2,2), (3,3,3), (4,4,4), (5,5,5);
Show no locks held by an open transaction + committed reads
of various types
Show no locks to begin with
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
-------------
CommittedRead
-------------
PK read, CR
begin;
select * from test.t1 where a=1;
a	b	c
1	1	1
Should be no locks held.
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
rollback;
ACC scan, CR
begin;
select * from test.t1 where b=4;
a	b	c
4	4	4
Should be no locks held.
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
rollback;
TUX scan, CR
begin;
select * from test.t1 where c > 4;
a	b	c
5	5	5
Should be no locks held.
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
rollback;
----------
SharedRead
----------
PK read, Shared
begin;
select * from test.t1 where a=1 lock in share mode;
a	b	c
1	1	1
One lock on primary
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
S	H	*	READ	0
rollback;
ACC scan, Shared
begin;
select * from test.t1 where b=4 lock in share mode;
a	b	c
4	4	4
One taken-over lock on primary
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
S	H	*	READ	0
rollback;
TUX scan, Shared
begin;
select * from test.t1 where c > 4 lock in share mode;
a	b	c
5	5	5
One taken-over lock on primary
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
S	H	*	READ	0
rollback;
Multiple rows
PK read, Shared
begin;
select * from test.t1 where a=1 lock in share mode;
a	b	c
1	1	1
select * from test.t1 where a=2 lock in share mode;
a	b	c
2	2	2
select * from test.t1 where a=3 lock in share mode;
a	b	c
3	3	3
select * from test.t1 where a=4 lock in share mode;
a	b	c
4	4	4
select * from test.t1 where a=5 lock in share mode;
a	b	c
5	5	5
Expect 5 row locks on primaries
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
S	H	*	READ	0
S	H	*	READ	0
S	H	*	READ	0
S	H	*	READ	0
S	H	*	READ	0
rollback;
ACC scan, Shared
begin;
select * from test.t1 lock in share mode;
Expect 5 row locks on primaries
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
S	H	*	READ	0
S	H	*	READ	0
S	H	*	READ	0
S	H	*	READ	0
S	H	*	READ	0
rollback;
TUX scan, Shared
begin;
select * from test.t1 lock in share mode;
Expect 5 row locks on primaries
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
S	H	*	READ	0
S	H	*	READ	0
S	H	*	READ	0
S	H	*	READ	0
S	H	*	READ	0
rollback;
--------------
Exclusive Read
--------------
PK read, Exclusive
begin;
select * from test.t1 where a=1 for update;
a	b	c
1	1	1
One lock on primary
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
X	H	*	READ	0
rollback;
ACC scan, Exclusive
begin;
select * from test.t1 where b=4 for update;
a	b	c
4	4	4
One taken-over lock on primary
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
X	H	*	READ	0
rollback;
TUX scan, Exclusive
begin;
select * from test.t1 where c > 4 for update;
a	b	c
5	5	5
One taken-over lock on primary
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
X	H	*	READ	0
rollback;
Multiple rows
PK read, Exclusive
begin;
select * from test.t1 where a=1 for update;
a	b	c
1	1	1
select * from test.t1 where a=2 for update;
a	b	c
2	2	2
select * from test.t1 where a=3 for update;
a	b	c
3	3	3
select * from test.t1 where a=4 for update;
a	b	c
4	4	4
select * from test.t1 where a=5 for update;
a	b	c
5	5	5
Expect 5 row locks on primaries
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
X	H	*	READ	0
X	H	*	READ	0
X	H	*	READ	0
X	H	*	READ	0
X	H	*	READ	0
rollback;
ACC scan, Exclusive
begin;
select * from test.t1 for update;
Expect 5 row locks on primaries
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
X	H	*	READ	0
X	H	*	READ	0
X	H	*	READ	0
X	H	*	READ	0
X	H	*	READ	0
rollback;
TUX scan, Exclusive
begin;
select * from test.t1 for update;
Expect 5 row locks on primaries
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
X	H	*	READ	0
X	H	*	READ	0
X	H	*	READ	0
X	H	*	READ	0
X	H	*	READ	0
rollback;
-----------
DML (I/U/D)
-----------
Insert
begin;
insert into test.t1 values (6,6,6);
Expect 1 lock per replica
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
X	H	*	INSERT	0
X	H	*	INSERT	0
rollback;
Update by PK
begin;
update test.t1 set b=50 where a=5;
Expect 1 lock per replica
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
X	H	*	UPDATE	0
X	H	*	UPDATE	0
rollback;
Update by ACC scan
begin;
update test.t1 set c=123 where b > 0;
Expect 5 locks per replica
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
rollback;
Update by TUX scan
begin;
update test.t1 set b=123 where c > 0;
Expect 5 locks per replica
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
rollback;
Delete by PK
begin;
delete from test.t1 where a=3;
Expect 1 lock per replica
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
X	H	*	DELETE	0
X	H	*	DELETE	0
rollback;
Delete by ACC scan
begin;
delete from test.t1 where b > 0;
Expect 5 locks per replica
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
rollback;
Update by TUX scan
begin;
delete from test.t1 where c > 0;
Expect 5 locks per replica
select * from ndbinfo.ordered_locks;
mode	state	detail	op	waiting
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
rollback;
----------------
Multi op per row
----------------
Shared PK read
begin;
select * from test.t1 where a=2 lock in share mode;
a	b	c
2	2	2
select * from test.t1 where a=2 lock in share mode;
a	b	c
2	2	2
select * from test.t1 where a=2 lock in share mode;
a	b	c
2	2	2
Expect 3 locks held on primary, only one is holder
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
S	H		READ	0
S	H		READ	0
S	H	*	READ	0
rollback;
Shared and Exclusive PK read
begin;
select * from test.t1 where a=2 lock in share mode;
a	b	c
2	2	2
select * from test.t1 where a=2 for update;
a	b	c
2	2	2
select * from test.t1 where a=2 lock in share mode;
a	b	c
2	2	2
Expect 3 locks held on primary, only one is holder
Holder is Shared, others are Xclusive
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		READ	0
X	H		READ	0
S	H	*	READ	0
rollback;
Multi Exclusive PK read
begin;
select * from test.t1 where a=2 for update;
a	b	c
2	2	2
select * from test.t1 where a=2 for update;
a	b	c
2	2	2
select * from test.t1 where a=2 for update;
a	b	c
2	2	2
Expect 3 locks held on primary, only one is holder
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		READ	0
X	H		READ	0
X	H	*	READ	0
rollback;
Multi scan shared
begin;
select * from test.t1 where a > 4 lock in share mode;
select * from test.t1 where a > 4 lock in share mode;
select * from test.t1 where a > 4 lock in share mode;
Expect 3 locks held on 1 row, only one is holder
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
S	H		READ	0
S	H		READ	0
S	H	*	READ	0
rollback;
Multi scan mixed
begin;
select * from test.t1 where a > 4 lock in share mode;
select * from test.t1 where a > 4 for update;
select * from test.t1 where a > 4 lock in share mode;
Expect 3 locks held on 1 row, only one is holder
Holder is shared
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		READ	0
X	H		READ	0
S	H	*	READ	0
rollback;
Multi scan exclusive
begin;
select * from test.t1 where a > 4 for update;
select * from test.t1 where a > 4 for update;
select * from test.t1 where a > 4 for update;
Expect 3 locks held on 1 row, only one is holder
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		READ	0
X	H		READ	0
X	H	*	READ	0
rollback;
ReadSh-Update PK
begin;
select * from test.t1 where a=2 lock in share mode;
update test.t1 set b=20 where a=2;
Expect 1 Primary S Read + 1 per replica EX Update
S is holder on primary replica, EX on Backup
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		UPDATE	0
S	H	*	READ	0
X	H	*	UPDATE	0
rollback;
ReadEx-Update PK
begin;
select * from test.t1 where a=2 for update;
update test.t1 set b=20 where a=2;
Expect 1 Primary EX Read + 1 per replica EX Update
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		UPDATE	0
X	H	*	READ	0
X	H	*	UPDATE	0
rollback;
ReadSh-Delete PK
begin;
select * from test.t1 where a=2 lock in share mode;
delete from test.t1 where a=2;
Expect 1 Primary S Read + 1 per replica EX Delete
S is holder on primary replica, EX on Backup
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		DELETE	0
X	H	*	DELETE	0
S	H	*	READ	0
rollback;
ReadEx-Update PK
begin;
select * from test.t1 where a=2 for update;
delete from test.t1 where a=2;
Expect 1 Primary EX Read + 1 per replica EX Delete
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		DELETE	0
X	H	*	DELETE	0
X	H	*	READ	0
rollback;
Insert-Update PK
begin;
insert into test.t1 values (6,6,6);
update test.t1 set b=60 where a=6;
Expect 2 locks per replica, held by Insert
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		UPDATE	0
X	H		UPDATE	0
X	H	*	INSERT	0
X	H	*	INSERT	0
rollback;
Insert-Delete PK
begin;
insert into test.t1 values (6,6,6);
delete from test.t1 where a=6;
Expect 2 locks per replica, held by Insert
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		DELETE	0
X	H		DELETE	0
X	H	*	INSERT	0
X	H	*	INSERT	0
rollback;
Update-Update PK
begin;
update test.t1 set b=45 where a=3;
update test.t1 set b=46 where a=3;
Expect 2 locks per replica
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		UPDATE	0
X	H		UPDATE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
rollback;
Update-Delete PK
begin;
update test.t1 set b=45 where a=3;
delete from test.t1 where a=3;
Expect 2 locks per replica held by Update
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		DELETE	0
X	H		DELETE	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
rollback;
Delete-Insert PK
begin;
delete from test.t1 where a=4;
insert into test.t1 values (4,44,44);
Expect 2 locks per replica held by Delete
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		INSERT	0
X	H		INSERT	0
X	H	*	DELETE	0
X	H	*	DELETE	0
rollback;
Delete-Insert-Delete PK
begin;
delete from test.t1 where a=4;
insert into test.t1 values (4,44,44);
delete from test.t1 where a=4;
Expect 3 locks per replica held by Delete
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		DELETE	0
X	H		DELETE	0
X	H		INSERT	0
X	H		INSERT	0
X	H	*	DELETE	0
X	H	*	DELETE	0
rollback;
Insert-Delete-Insert PK
begin;
insert into test.t1 values (6,66,66);
delete from test.t1 where a=6;
insert into test.t1 values (6,7,8);
Expect 3 locks per replica, held by Insert
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	H		DELETE	0
X	H		DELETE	0
X	H		INSERT	0
X	H		INSERT	0
X	H	*	INSERT	0
X	H	*	INSERT	0
rollback;
-----------------
Multi-transaction
-----------------
Shared reads PK
begin;
select * from test.t1 where a=1 lock in share mode;
a	b	c
1	1	1
begin;
select * from test.t1 where a=1 lock in share mode;
a	b	c
1	1	1
begin;
select * from test.t1 where a=1 lock in share mode;
a	b	c
1	1	1
Expect 3 row locks taken, one is owner
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
S	H		READ	0
S	H		READ	0
S	H	*	READ	0
Expect 3 transactions
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
3
rollback;
rollback;
rollback;
**********
Contention
**********
PK SH vs PK EX
begin;
select * from test.t1 where a=1 lock in share mode;
a	b	c
1	1	1
begin;
select * from test.t1 where a=1 for update;;
Expect : X waiting for SH lock
2 transactions
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	W		READ	1
S	H	*	READ	0
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
2
rollback;
a	b	c
1	1	1
rollback;
PK EX vs PK SH
begin;
select * from test.t1 where a=1 for update;
a	b	c
1	1	1
begin;
select * from test.t1 where a=1 lock in share mode;;
Expect : SH waiting for X lock
2 transactions
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
S	W		READ	1
X	H	*	READ	0
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
2
rollback;
a	b	c
1	1	1
rollback;
PK EX vs PK EX
begin;
select * from test.t1 where a=1 for update;
a	b	c
1	1	1
begin;
select * from test.t1 where a=1 for update;;
Expect : X waiting for X lock
2 transactions
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	W		READ	1
X	H	*	READ	0
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
2
rollback;
a	b	c
1	1	1
rollback;
Insert vs PK SH read
begin;
insert into test.t1 values (7,7,7);
begin;
select * from test.t1 where a=7 lock in share mode;;
Expect : S waiting for X lock
2 transactions
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
S	W		READ	1
X	H	*	INSERT	0
X	H	*	INSERT	0
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
2
rollback;
a	b	c
rollback;
Update vs PK SH read
begin;
update test.t1 set b=55 where a=5;
begin;
select * from test.t1 where a=5 lock in share mode;;
Expect : S waiting for X lock
2 transactions
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
S	W		READ	1
X	H	*	UPDATE	0
X	H	*	UPDATE	0
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
2
rollback;
a	b	c
5	5	5
rollback;
PK SH read vs Update
begin;
select * from test.t1 where a=5 lock in share mode;
a	b	c
5	5	5
begin;
update test.t1 set b=55 where a=5;;
Expect : X waiting for S lock
2 transactions
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	W		UPDATE	1
S	H	*	READ	0
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
2
rollback;
rollback;
Delete vs PK SH read
begin;
delete from test.t1 where a=5;
begin;
select * from test.t1 where a=5 lock in share mode;;
Expect : S waiting for X lock
2 transactions
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
S	W		READ	1
X	H	*	DELETE	0
X	H	*	DELETE	0
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
2
rollback;
a	b	c
5	5	5
rollback;
PK SH read vs Delete
begin;
select * from test.t1 where a=5 lock in share mode;
a	b	c
5	5	5
begin;
delete from test.t1 where a=5;;
Expect : X waiting for S lock
2 transactions
select * from ndbinfo.ordered_locks order by detail, op;
mode	state	detail	op	waiting
X	W		DELETE	1
S	H	*	READ	0
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
2
rollback;
rollback;
PK SH read vs EX scan
begin;
select * from test.t1 where a=5 lock in share mode;
a	b	c
5	5	5
begin;
select * from test.t1 order by a for update;;
Expect : 5-1 X locks from scan
1   X lock waiting from scan
1   S lock held by read
2 transactions
select mode, state, detail, waiting from ndbinfo.ordered_locks order by detail, mode, op;
mode	state	detail	waiting
X	W		1
S	H	*	0
X	H	*	0
X	H	*	0
X	H	*	0
X	H	*	0
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
2
rollback;
a	b	c
1	1	1
2	2	2
3	3	3
4	4	4
5	5	5
rollback;
PK EX read vs SH scan
begin;
select * from test.t1 where a=5 for update;
a	b	c
5	5	5
begin;
select * from test.t1 order by a lock in share mode;;
Expect : 5-1 S locks from scan
1   S lock waiting from scan
1   X lock held by read
2 transactions
select mode, state, detail, waiting from ndbinfo.ordered_locks order by detail, mode, op;
mode	state	detail	waiting
S	W		1
S	H	*	0
S	H	*	0
S	H	*	0
S	H	*	0
X	H	*	0
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
2
rollback;
a	b	c
1	1	1
2	2	2
3	3	3
4	4	4
5	5	5
rollback;
SH read, SH read, SH upgrade (blocked)
begin;
select * from test.t1 where a=5 lock in share mode;
a	b	c
5	5	5
begin;
select * from test.t1 where a=5 lock in share mode;
a	b	c
5	5	5
Upgrade attempt will block as other trans has
shared lock on row
select * from test.t1 where a=5 for update;;
2 shared locks on row
1 ex read waiting
2 transactions
select * from ndbinfo.ordered_locks order by detail, mode, op;
mode	state	detail	op	waiting
S	H		READ	0
X	W		READ	1
S	H	*	READ	0
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
2
rollback;
a	b	c
5	5	5
rollback;
drop table test.t1;
***********
Blob tables
***********
create table test.t1 (a int primary key, b int, c text) engine=ndb;
insert into test.t1 values (1, 1, repeat('SSG',300));
Show PK CR leaves no locks 
begin;
select a,b,length(c) from test.t1 where a=1;
a	b	length(c)
1	1	900
select * from ndbinfo.ordered_locks order by detail, mode, op;
mode	state	detail	op	waiting
rollback;
Show PK SH lock
begin;
select a,b,length(c) from test.t1 where a=1 lock in share mode;
a	b	length(c)
1	1	900
Expect Shared lock on main table row only
select * from ndbinfo.ordered_locks order by detail, mode, op;
mode	state	detail	op	waiting
S	H	*	READ	0
rollback;
Show PK EX lock
begin;
select a,b,length(c) from test.t1 where a=1 for update;
a	b	length(c)
1	1	900
Expect Exclusive lock on main table row only
select * from ndbinfo.ordered_locks order by detail, mode, op;
mode	state	detail	op	waiting
X	H	*	READ	0
rollback;
Show insert locks
begin;
insert into test.t1 values (2,2,repeat('TSG', 300));
Expect Exclusive locks on all replicas of main + part row
select * from ndbinfo.ordered_locks order by detail, mode, op;
mode	state	detail	op	waiting
X	H		UPDATE	0
X	H		UPDATE	0
X	H	*	INSERT	0
X	H	*	INSERT	0
X	H	*	INSERT	0
X	H	*	INSERT	0
rollback;
Show update locks
begin;
update test.t1 set c=repeat('FSG', 300) where a=1;
Expect Exclusive locks on all replicas of main + part row
Various : Reads, Updates on main, Updates on parts
Part(s) may have delete + insert rather than update
select * from ndbinfo.ordered_locks order by detail,op;
mode	state	detail	op	waiting
X	H		INSERT	0
X	H		INSERT	0
X	H		READ	0
X	H		UPDATE	0
X	H		UPDATE	0
X	H		UPDATE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	READ	0
X	H	*	UPDATE	0
rollback;
Show delete locks
begin;
delete from test.t1 where a=1;
Expect Exclusive locks on all replicas of main + part row
select * from ndbinfo.ordered_locks order by detail,op;
mode	state	detail	op	waiting
X	H		DELETE	0
X	H		READ	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	READ	0
rollback;
Show CR takes a lock transiently
Take exclusive lock
begin;
select a,b,length(c) from test.t1 where a=1 for update;
a	b	length(c)
1	1	900
select a,b,length(c) from test.t1 where a=1;;
Expect Shared waiting for Exclusive on main table row.
select * from ndbinfo.ordered_locks order by detail,op;
mode	state	detail	op	waiting
S	W		READ	1
X	H	*	READ	0
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
2
rollback;
a	b	length(c)
1	1	900
rollback;
drop table test.t1;
***********
Unique keys
***********
create table test.t1 (a int primary key, b int, c int, unique(c)) engine=ndb;
insert into test.t1 values (5,5,5);
Show UK CR takes shared locks
begin;
select * from test.t1 where c=5;
a	b	c
5	5	5
select * from ndbinfo.ordered_locks order by detail,op;
mode	state	detail	op	waiting
S	H	*	READ	0
S	H	*	READ	0
select count(distinct tableid) from ndbinfo.cluster_locks;
count(distinct tableid)
2
rollback;
Show UK EX read
begin;
select * from test.t1 where c=5 for update;
a	b	c
5	5	5
select * from ndbinfo.ordered_locks order by detail,op;
mode	state	detail	op	waiting
X	H	*	READ	0
X	H	*	READ	0
select count(distinct tableid) from ndbinfo.cluster_locks;
count(distinct tableid)
2
rollback;
Show UK update, not of UK column
begin;
update test.t1 set b=55 where c=5;
select * from ndbinfo.ordered_locks order by detail,op;
mode	state	detail	op	waiting
X	H	*	READ	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
select count(distinct tableid) from ndbinfo.cluster_locks;
count(distinct tableid)
2
rollback;
Show UK update, of UK column
begin;
update test.t1 set c=55 where c=5;
Read by UK @ primary
Read @ UK
Update of main @ both
Delete of old UK @ both
Insert of new UK @ both 
select * from ndbinfo.ordered_locks order by detail,op;
mode	state	detail	op	waiting
X	H		DELETE	0
X	H		UPDATE	0
X	H	*	DELETE	0
X	H	*	INSERT	0
X	H	*	INSERT	0
X	H	*	READ	0
X	H	*	READ	0
X	H	*	UPDATE	0
select count(distinct tableid) from ndbinfo.cluster_locks;
count(distinct tableid)
2
rollback;
Show UK delete
begin;
delete from test.t1 where c=5;
select * from ndbinfo.ordered_locks order by detail,op;
mode	state	detail	op	waiting
X	H		DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	DELETE	0
X	H	*	READ	0
select count(distinct tableid) from ndbinfo.cluster_locks;
count(distinct tableid)
2
rollback;
Show PK update vs UK update
begin;
update test.t1 set b=400 where a=5;
begin;
update test.t1 set b=444 where c=5;;
Expect PK update holding lock@each replica
Expect UK read holding lock on UK table + waiting for
lock on UK table primary
select * from ndbinfo.ordered_locks order by detail,op;
mode	state	detail	op	waiting
X	W		UPDATE	1
X	H	*	READ	0
X	H	*	UPDATE	0
X	H	*	UPDATE	0
select count(distinct transid) from ndbinfo.cluster_locks;
count(distinct transid)
2
select count(distinct tableid) from ndbinfo.cluster_locks;
count(distinct tableid)
2
rollback;
rollback;
drop table test.t1;
********
Deadlock
********
create table test.t1 (a int primary key, b int) engine=ndb;
insert into test.t1 values (1,1), (2,2);
begin;
select * from test.t1 where a=1 for update;
a	b
1	1
begin;
select * from test.t1 where a=2 for update;
a	b
2	2
select * from test.t1 where a=2 for update;;
select * from test.t1 where a=1 for update;;
Show using cluster_locks to find the deadlock

create view transaction_dependencies as
select a.transid as waiting_transid, b.transid as holding_transid 
from ndbinfo.cluster_locks a join 
ndbinfo.cluster_locks b
on a.node_id = b.node_id and
a.block_instance = b.block_instance and
a.waiting_for = b.lock_num;
select * from transaction_dependencies;
create view second_level_dependencies as
select a.waiting_transid as waiting_transid, 
b.holding_transid as holding_transid,
a.holding_transid as other
from transaction_dependencies a join transaction_dependencies b
on a.holding_transid = b.waiting_transid;
select * from second_level_dependencies;
create view 2_way_deadlocks_found as
select * 
from second_level_dependencies
where waiting_transid = holding_transid;
select * from 2_way_deadlocks_found;
create view unique_2_way_deadlocks as
select distinct
if (waiting_transid < other,
waiting_transid,
other),
if (waiting_transid < other,
other,
waiting_transid)
from 2_way_deadlocks_found;
select * from unique_2_way_deadlocks;
select count(1)
from unique_2_way_deadlocks;
count(1)
1
drop view unique_2_way_deadlocks;
drop view 2_way_deadlocks_found;
drop view second_level_dependencies;
drop view transaction_dependencies;
rollback;
rollback;
drop table test.t1;
drop view ndbinfo.ordered_locks;