GitHub user dosubot[bot] added a comment to the discussion: Superset is not able to recognise the NULL datatype of any column
<!-- Answer --> Superset shows the `timestamp` column as UNKNOWN because the Hydrolix connector (or the underlying database) reports its datatype as NULL. Superset relies on the connector to provide explicit type information; if the type is NULL or ambiguous, Superset can't map it to a recognized type and marks it as UNKNOWN, which breaks time-based features like time range queries and chart rendering. There isn't a built-in way in Superset to manually override or fix this in the UI or API—column types are inferred directly from the database metadata and engine spec mappings. To resolve this, make sure the source database (Hydrolix) provides an explicit and correct type for the `timestamp` column. Alternatively, you could patch the engine spec for the Hydrolix connector to handle NULL or ambiguous types more gracefully, but this requires backend code changes. Superset does not have Hydrolix-specific logic for this and uses the generic SQLAlchemy pathway for type inference. If the column remains UNKNOWN, it cannot be used for time filters or as a temporal column in charts. [Reference: Superset code and engine spec handling](https://github.com/apache/superset/blob/829e4d92d91ceae4b43b1ed3b063ffe45377799c/superset/connectors/sqla/utils.py) <!-- Dosu Comment Footer --> *To reply, just mention [@dosu](https://go.dosu.dev/dosubot).* --- <sup>How did I do? [Good](https://app.dosu.dev/response-feedback/805e81b9-279e-4139-b24c-402c81f5421c?feedback_type=great_response) | [Irrelevant](https://app.dosu.dev/response-feedback/805e81b9-279e-4139-b24c-402c81f5421c?feedback_type=irrelevant_answer) | [Incorrect](https://app.dosu.dev/response-feedback/805e81b9-279e-4139-b24c-402c81f5421c?feedback_type=incorrect_sources) | [Verbose](https://app.dosu.dev/response-feedback/805e81b9-279e-4139-b24c-402c81f5421c?feedback_type=too_verbose) | [Hallucination](https://app.dosu.dev/response-feedback/805e81b9-279e-4139-b24c-402c81f5421c?feedback_type=hallucination) | [Report 🐛](https://app.dosu.dev/response-feedback/805e81b9-279e-4139-b24c-402c81f5421c?feedback_type=bug_report) | [Other](https://app.dosu.dev/response-feedback/805e81b9-279e-4139-b24c-402c81f5421c?feedback_type=other)</sup> [](https://app.dosu.dev/a28d3c7e-a9d3-459e-9fb6-3a6f9ff4f357/ask?utm_source=github)& nbsp;[](https://go.dosu.dev/discord-bot) [](https://twitter.com/intent/tweet?text=%40dosu_ai%20helped%20me%20solve%20this%20issue!&url=https%3A//github.com/apache/superset/discussions/35188) GitHub link: https://github.com/apache/superset/discussions/35188#discussioncomment-14443377 ---- This is an automatically sent email for [email protected]. To unsubscribe, please send an email to: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
