v.24.3Improvement
Allow Enum Declarations in External Data Structures for Query Processing
Allow declaring Enums in the structure of external data for query processing (this is an immediate temporary table that you can provide for your query). #57857 (Duc Canh Le).
Why it matters
This feature solves the limitation of not being able to specify Enum types in the schema of external data passed to queries. By supporting Enums, users can better represent categorical data with defined sets of values, improving query accuracy and usability when working with temporary external data.How to use it
When providing external data for a query (such as using theWITH clause or external tables), you can now define columns with Enum types in the structure specification. This enables ClickHouse to correctly parse and process columns with Enum values in immediate temporary tables during query execution.