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/). 

# HyperLogLog functions
<a name="hyperloglog-functions"></a>

Following, you can find descriptions for the HyperLogLog functions for SQL that Amazon Redshift supports.

**Topics**
+ [HLL function](r_HLL_function.md)
+ [HLL\_CREATE\_SKETCH function](r_HLL_CREATE_SKETCH.md)
+ [HLL\_CARDINALITY function](r_HLL_CARDINALITY.md)
+ [HLL\_COMBINE function](r_HLL_COMBINE.md)
+ [HLL\_COMBINE\_SKETCHES function](r_HLL_COMBINE_SKETCHES.md)