Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the [ blog post ](https://aws.amazon.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/). 

# PG\$1TERMINATE\$1BACKEND
<a name="PG_TERMINATE_BACKEND"></a>

Terminates a session. You can terminate a session owned by your user. A superuser can terminate any session.

## Syntax
<a name="PG_TERMINATE_BACKEND-synopsis"></a>

```
pg_terminate_backend( pid )
```

## Arguments
<a name="PG_TERMINATE_BACKEND-arguments"></a>

*pid*  
The process ID of the session to be terminated. Requires an `INTEGER` value.

## Return type
<a name="PG_TERMINATE_BACKEND-return-type"></a>

None

## Usage notes
<a name="PG_TERMINATE_BACKEND-usage-notes"></a>

 If you are close to reaching the limit for concurrent connections, use PG\$1TERMINATE\$1BACKEND to terminate idle sessions and free up the connections. For more information, see [Limits in Amazon Redshift](https://docs.aws.amazon.com/redshift/latest/mgmt/amazon-redshift-limits.html). 

If queries in multiple sessions hold locks on the same table, you can use PG\$1TERMINATE\$1BACKEND to terminate one of the sessions, which forces any currently running transactions in the terminated session to release all locks and roll back the transaction. Query the PG\$1LOCKS catalog table to view currently held locks. 

If a query is not in a transaction block (BEGIN … END), you can cancel the query by using the [CANCEL](r_CANCEL.md) command or the [PG\$1CANCEL\$1BACKEND](PG_CANCEL_BACKEND.md) function. 

## Examples
<a name="PG_TERMINATE_BACKEND-example"></a>

To query the SVV\$1TRANSACTIONS table to view all locks in effect for current transactions, use the following example.

```
SELECT * FROM svv_transactions;

+-----------+--------+-------+------+---------------------+-----------------+----------------------+----------+---------+
| txn_owner | txn_db |  xid  | pid  |      txn_start      |    lock_mode    | lockable_object_type | relation | granted |
+-----------+--------+-------+------+---------------------+-----------------+----------------------+----------+---------+
| rsuser    | dev    | 96178 | 8585 | 2017-04-12 20:13:07 | AccessShareLock | relation             |    51940 | true    |
| rsuser    | dev    | 96178 | 8585 | 2017-04-12 20:13:07 | AccessShareLock | relation             |    52000 | true    |
| rsuser    | dev    | 96178 | 8585 | 2017-04-12 20:13:07 | AccessShareLock | relation             |   108623 | true    |
| rsuser    | dev    | 96178 | 8585 | 2017-04-12 20:13:07 | ExclusiveLock   | transactionid        |          | true    |
+-----------+--------+-------+------+---------------------+-----------------+----------------------+----------+---------+
```

TO terminate the session holding the locks, use the following example.

```
SELECT PG_TERMINATE_BACKEND(8585); 
```