cloventt opened a new issue #9911: URL: https://github.com/apache/druid/issues/9911
### Affected Version 0.17.0 ### Description We have been using injective lookups to perform a one-to-one mapping between an ID and some model data. However, when we construct a query to order results by the mapped value, the results are returned ordered by the original dimension value. For example, if injective lookups perform this mapping: ``` // key -> value 1 -> C 2 -> B 3 -> A ``` Then when making a query ordering by `value`, we would expect to see: ``` A B C ``` But what we actually see is: ``` C B A ``` The results are ordered by the value of key, not value. This issue does not seem to occur for non-injective lookups. However when we change to use a non-injective lookup, we see a performance hit and a considerable increase in heap usage and GC time on the historical while the query is running. Given how injective lookups are processed, this might be expected behaviour. However as far as I can tell this behaviour is not mentioned in the documentation. ---------------------------------------------------------------- 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 --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@druid.apache.org For additional commands, e-mail: commits-h...@druid.apache.org
