techdocsmith commented on code in PR #12710: URL: https://github.com/apache/druid/pull/12710#discussion_r908883882
########## docs/querying/sql.md: ########## @@ -168,14 +168,11 @@ There are two important factors that can affect the performance of queries that ## UNION ALL -The "UNION ALL" operator fuses multiple queries together. Druid SQL supports the UNION ALL operator in two situations: -top-level and table-level. Queries that use UNION ALL in any other way will not be able to execute. +The UNION ALL operator fuses multiple queries together. Druid SQL supports the UNION ALL operator in two situations: top-level and table-level, as described below. Queries that use UNION ALL in any other way will not execute. Review Comment: I wonder about the usage "fuses" here. ```suggestion The UNION ALL operator fuses multiple queries together. Druid SQL supports the UNION ALL operator in two situations: top-level and table-level, as described below. Queries that use UNION ALL in any other way will fail. ``` ########## docs/querying/sql.md: ########## @@ -185,20 +182,17 @@ UNION ALL SELECT COUNT(*) FROM tbl WHERE my_column = 'value2' ``` -With top-level UNION ALL, no further processing can be done after the UNION ALL. For example, the results of the -UNION ALL cannot have GROUP BY, ORDER BY, or any other operators applied to them. +> With top-level queries, you can't apply GROUP BY, ORDER BY, or any other operator to the results of a UNION ALL. Review Comment: I wonder if the "no further processing" is is necessary. It does get lost in the revision. ########## docs/querying/sql.md: ########## @@ -168,14 +168,11 @@ There are two important factors that can affect the performance of queries that ## UNION ALL -The "UNION ALL" operator fuses multiple queries together. Druid SQL supports the UNION ALL operator in two situations: -top-level and table-level. Queries that use UNION ALL in any other way will not be able to execute. +The UNION ALL operator fuses multiple queries together. Druid SQL supports the UNION ALL operator in two situations: top-level and table-level, as described below. Queries that use UNION ALL in any other way will not execute. ### Top-level -UNION ALL can be used at the very top outer layer of a SQL query (not in a subquery, and not in the FROM clause). In -this case, the underlying queries will be run separately, back to back. Their results will be concatenated together -and appear one after the other. +You can use UNION ALL at the very top outer layer of a SQL query - not in a subquery, and not in the FROM clause. The underlying queries run separately, back to back. Their results are concatenated together and appear one after the other. Review Comment: ```suggestion You can use UNION ALL at the very top outer layer of a SQL query - not in a subquery, and not in the FROM clause. The underlying queries run sequentially. Druid concatenates their results so that they appear one after the other. ``` -- 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]
