ffacs commented on PR #2010: URL: https://github.com/apache/orc/pull/2010#issuecomment-2304198383
> > @taiyang-li Hi, thank you for opening a PR! It seems that the time complexity not changed. Do writing cost a lot on sorting? After all, the size of dictionary shouldn't be large when we try to use dictionary encoding. > > @ffacs I had measured about this. From flamegraph we could see that `std::map::insert` takes most of time. Notice that `std::map::insert` is executed even if key is duplicated. Oh yes, std::map takes $$O(n \ \log(key))$$, but sort takes only $$O(n + key\ \log(Key))$$ -- 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]
