ravisharm opened a new pull request, #17931: URL: https://github.com/apache/druid/pull/17931
Fixes #17171. ### Description Emit number of rows scanned while addressing the query as a response header. This value can be used to quantify the cost of a Druid query and can greatly help in determining costly queries. This PR modifies the query engine class of the various query types to compute the number of scanned rows which is then passed to the higher layers via response context. Eventually, number of rows scanned is emitted as header X-Num-Scanned-Rows. #### Release note While responding to any Druid query, Druid response now contains a new header X-Num-Scanned-Rows that gives number of rows scanned after applying all the filters in the query. The value of this header can be used as one of the signals to quantify the cost of a Druid query. This PR has: - [x ] been self-reviewed. - [ ] added documentation for new or modified features or behaviors. - [ x] a release note entry in the PR description. - [x ] been tested in a test Druid cluster. -- 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]
