clintropolis commented on code in PR #15245: URL: https://github.com/apache/druid/pull/15245#discussion_r1378475462
########## docs/querying/multi-value-dimensions.md: ########## @@ -61,20 +77,81 @@ By default, Druid sorts values in multi-value dimensions. This behavior is contr See [Dimension Objects](../ingestion/ingestion-spec.md#dimension-objects) for information on configuring multi-value handling. +### SQL-based ingestion +Multi-value dimensions can also be inserted with [SQL-based ingestion](../multi-stage-query/index.md). The multi-stage query engine does not have direct handling of class Druid multi-value dimensions. A special pair of functions, `MV_TO_ARRAY` which converts multi-value dimensions into `VARCHAR ARRAY` and `ARRAY_TO_MV` to coerce them back into `VARCHAR` exist to enable handling these types. Multi-value handling is not available when using the multi-stage query engine to insert data. Review Comment: I guess I was thinking of `groupByEnableMultiValueUnnesting` which looking at the code is actually allowed by default, and it is the web-console which sets it to false for MSQ queries by default. I'll try to clarify stuff -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
