FrankChen021 commented on code in PR #20183: URL: https://github.com/apache/druid/pull/20183#discussion_r4359604777
########## docs/querying/sql-metadata-tables.md: ########## @@ -135,10 +135,61 @@ WHERE "IS_AGGREGATOR" = 'YES' The "sys" schema provides visibility into Druid segments, servers and tasks. :::info - Note: "sys" tables do not currently support Druid-specific functions like `TIME_PARSE` and - `APPROX_QUANTILE_DS`. Only standard SQL functions can be used. + By default, "sys" tables use the SQL-layer execution path and support only standard SQL functions. You can enable + experimental [native query execution](#native-query-execution) for supported system tables, which enables expressions and + aggregations that the native SQL engine can translate. +::: + +### Native query execution + +:::caution Experimental +Native query execution for system tables is an experimental, opt-in feature. Its behavior and interfaces may change. ::: +The native SQL engine can plan supported system tables as native datasources. To enable this behavior for a query, set +`allowNativeFunctionsForSystemTables` to `true` in the SQL query context: Review Comment: Initially, I used the name `useNativeEngineForSystemTables`, however, for long term evolution, I found that the dart engine might be the better(it already has the exeuction path that fans out scan queries and aggregation sub queries), considering that, I change the name to current one. -- 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]
