leventov commented on a change in pull request #7185: Avoid many unnecessary materializations of collections of 'all segments in cluster' cardinality URL: https://github.com/apache/incubator-druid/pull/7185#discussion_r263142135
########## File path: server/src/main/java/org/apache/druid/metadata/MetadataSegmentManager.java ########## @@ -59,6 +60,8 @@ Collection<ImmutableDruidDataSource> getDataSources(); + Iterable<DataSegment> iterateAllSegments(); Review comment: I intentionally renamed the method to not start with "get". Although formally it returns a lambda whose creation is cheap, iteration itself involves `flatMap()`, creation of many streams, and therefore is not so cheap. See item 16 in the "Naming" section in the [working draft of checklist](https://docs.google.com/document/d/17EEKT6fih9Dd5NfXjBoECcKbVp1eOB2vb3jKqTF9pPc/edit). I will add Javadoc to this method to additionally highlight that the iteration is not super cheap (however, far cheaper than materialization to collections that was done before.) ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@druid.apache.org For additional commands, e-mail: commits-h...@druid.apache.org
