v.25.9New Feature
Support the oneof
Support theoneofindicator inProtobufinputs. A special column may be used to indicate the presence of part of oneof. If a message contains oneof andinput_format_protobuf_oneof_presenceis set, ClickHouse fills column that indicates which field of oneof was found. #82885 (Ilya Golshtein).
Why it matters
This feature enables users to identify which specific field of aoneof in Protobuf messages has been set when importing data into ClickHouse. It resolves the problem of ambiguity when multiple fields in a oneof are possible but only one can be present, improving data clarity and enabling more precise queries.How to use it
To enable this feature, set the parameterinput_format_protobuf_oneof_presence when using the Protobuf input format. ClickHouse will then populate a special column that indicates which oneof field was found in each message.