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://amazonaws-china.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. 

# error\_on\_nondeterministic\_update
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## Values (default in bold)
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**false**, true

## Description
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Specifies whether UPDATE queries with multiple matches per row return an error.

## Example
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```
SET error_on_nondeterministic_update TO true;
            
CREATE TABLE t1(x1 int, y1 int);

CREATE TABLE t2(x2 int, y2 int);

INSERT INTO t1 VALUES (1,10), (2,20), (3,30);

INSERT INTO t2 VALUES (2,40), (2,50);

UPDATE t1 SET y1=y2 FROM t2 WHERE x1=x2; 

ERROR: Found multiple matches to update the same tuple.
```