Presto supports dynamically registered User Defined Functions (UDFs) since 2020. Over the years, we used this framework to add support for SQL UDFs and remote / external UDFs. One common community request in the UDF domain is to support Hive UDFs. Many companies have legacy Hive pipelines, and engineers who are familiar with HQL and Hive UDFs. With remote UDF, one can implement Hive UDF support as UDFs running on the remote cluster. But since HiveUDFs are written in Java, we can also run them inside the engine. We extended the dynamic UDF framework to support Java UDFs, and used this new extension to add HiveUDF support in Presto. With this feature, users can directly use their familiar HiveUDFs and UDAFs in their Presto query.
Presto has been widely used at Bytedance in several ways such as in the data warehouse, BI tools, ads etc. And, the Presto team at Bytedance has also delivered many key features and optimizations such as the Hive UDF wrapper, coordinator, runtime filter and so on which extend Presto usages and enhance Presto stabilities. Nowadays, most companies will use both Hive (or Spark) and Presto together. But Presto UDFs have very different syntax and internal mechanisms compared with Hive UDFs. This restricts Presto usage while users need to maintain 2 kinds of functions. In this talk, we will present a way to execute Hive UDF/UDAF inside Presto.