Viewing transaction locks

As a Hive administrator, you can get troubleshooting information about locks on a table, partition, or schema.

Enter a Hive query to check table locks.
```
SHOW LOCKS mytable EXTENDED;         
```

Check partition locks.

SHOW LOCKS mytable PARTITION(ds='2018-05-01', hr='12') EXTENDED;

Check schema locks.
```
SHOW LOCKS SCHEMA mydatabase;
```
Output generally appears as follows.
- Database name
- Table name
- Partition, if the table is partitioned
- Lock state:
  - Acquired - transaction initiator hold the lock
  - Waiting - transaction initiator is waiting for the lock
  - Aborted - the lock has timed out but has not yet been cleaned
- Lock type:
  - Exclusive - the lock cannot be shared
  - Shared_read - the lock cannot be shared with any number of other shared_read locks
  - Shared_write - the lock may be shared by any number of other shared_read locks but not with other shared_write locks
- Transaction ID associated with the lock, if one exists
- Last time lock holder sent a heartbeat
- Time the lock was acquired, if it has been acquired
- Hive user who requested the lock
- Host machine or virtual machine on which the Hive user is running a Hive client
- Blocked By ID - ID of the lock causing current lock to be in Waiting mode, if the lock is in this mode