gianm commented on code in PR #15245: URL: https://github.com/apache/druid/pull/15245#discussion_r1379285860
########## docs/querying/multi-value-dimensions.md: ########## @@ -78,7 +78,7 @@ 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. +Multi-value dimensions can also be inserted with [SQL-based ingestion](../multi-stage-query/index.md). The functions `MV_TO_ARRAY` and `ARRAY_TO_MV` can assist in converting `VARCHAR` to `VARCHAR ARRAY` and `VARCHAR ARRAY` into `VARCHAR` respectively. Multi-value handling is not available when using the multi-stage query engine to insert data. Review Comment: "Multi-value handling" in English like that I think will be confusing. It sounds like we're saying that multi-value dimensions cannot be handled by MSQ. Probably clearer to use `multiValueHandling` to make it clear we're talking about a parameter. ########## docs/querying/post-aggregations.md: ########## @@ -101,10 +101,13 @@ The expression post-aggregator is defined using a Druid [expression](math-expr.m "type": "expression", "name": <output_name>, "expression": <post-aggregation expression>, - "ordering" : <null (default), or "numericFirst"> + "ordering": <null (default), or "numericFirst">, + "outputType": <output value type of expression> } ``` +Output type is optional, and can be any native Druid type: `LONG`, `FLOAT`, `DOUBLE`, `STRING`, `ARRAY` types (e.g. `ARRAY<LONG>`), or `COMPLEX` types (e.g. `COMPLEX<json>`). Review Comment: This raises questions that the docs should answer: - What benefit is there to providing `outputType`? - What happens if `outputType` different from the type of `expression`? Error, cast, something else? -- 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]
