Amazon Redshift will no longer support the use of Python UDFs after June 30, 2026. We will start enforcing it in phases. For more information on the details of Python end of life and migration options, 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/) that was published on June 30, 2025. 

# PG\_TERMINATE\_BACKEND
<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\_TERMINATE\_BACKEND 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\_TERMINATE\_BACKEND 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\_LOCKS 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\_CANCEL\_BACKEND](PG_CANCEL_BACKEND.md) function. 

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

To query the SVV\_TRANSACTIONS 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); 
```