Riza Suminto has posted comments on this change. ( http://gerrit.cloudera.org:8080/17980 )
Change subject: IMPALA-10984: Improve performance of TimestampValue::ToString ...................................................................... Patch Set 2: (4 comments) Thank you, Csaba, for the comments! Will address them in next patch set. http://gerrit.cloudera.org:8080/#/c/17980/2//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/17980/2//COMMIT_MSG@49 PS2, Line 49: 4.91 4.91 0.128X 0.128X 0.128X : from_unixtime(0,'yyyy-MM-dd HH:mm:ss') > Wonder why this became slow during the last patch. Some unoptimal change in patch set 2. Might be the reinterpret_cast thing from uint8_t* to char* in TimestampValue::ToStringVal. Will take a look at it during next iteration. http://gerrit.cloudera.org:8080/#/c/17980/2/be/src/runtime/timestamp-parse-util.cc File be/src/runtime/timestamp-parse-util.cc: http://gerrit.cloudera.org:8080/#/c/17980/2/be/src/runtime/timestamp-parse-util.cc@341 PS2, Line 341: tmp_buff > I think that we can easily avoid using the tmp_buff here. Good point. Having on-stack char array should also drop the necessity of tmp_string_ in FunctionContextImpl. Will try it in next patch set. http://gerrit.cloudera.org:8080/#/c/17980/2/be/src/runtime/timestamp-parse-util.cc@344 PS2, Line 344: for (int i = written_length; i < tok.len; i++) { : *(dst + pos) = '0'; : pos++; : } > If I understand this correctly, then we are writing to the end of the buffe That is correct. http://gerrit.cloudera.org:8080/#/c/17980/2/be/src/runtime/timestamp-parse-util.cc@351 PS2, Line 351: DCHECK_LE(pos, max_length) << "Maximum buffer length exceeded!"; > I am a bit concerned that at the time we hit this DCHECK, we have already w Will do. -- To view, visit http://gerrit.cloudera.org:8080/17980 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I4fcb4545d9c9a3fdb38c4db58bb4b1321a429d61 Gerrit-Change-Number: 17980 Gerrit-PatchSet: 2 Gerrit-Owner: Riza Suminto <riza.sumi...@cloudera.com> Gerrit-Reviewer: Bikramjeet Vig <bikramjeet....@cloudera.com> Gerrit-Reviewer: Csaba Ringhofer <csringho...@cloudera.com> Gerrit-Reviewer: Impala Public Jenkins <impala-public-jenk...@cloudera.com> Gerrit-Reviewer: Kurt Deschler <kdesc...@cloudera.com> Gerrit-Reviewer: Riza Suminto <riza.sumi...@cloudera.com> Gerrit-Comment-Date: Thu, 28 Oct 2021 15:38:55 +0000 Gerrit-HasComments: Yes
