wesleydeng has posted comments on this change. ( http://gerrit.cloudera.org:8080/16719 )
Change subject: IMPALA-10323: use snprintf instead of lexical_cast to cast to string ...................................................................... Patch Set 1: (1 comment) > (1 comment) use buffer may result in lock contention in multi-thread mode where I want to improve performance. To save memory, I have another proposal: May be we can define 3 level char size : 5,10,20, for bigint value , if value<99999999999 && value > -999999999, then change char_size to 10; else if value <99999 && value>-9999, than change char size to 5; http://gerrit.cloudera.org:8080/#/c/16719/1//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/16719/1//COMMIT_MSG@10 PS1, Line 10: performance can be improved significantly in : multi-thread mode(mt_dop mode). In contrast, performance using : lexical_cast decreased seriously in multi-thread mode. > Do you have any measurements to see what is the order of magnitude of this As it show in IMPALA-10323, use snprintf can save 90% time compared with using lexical_cast in mt_dop=8 mode -- To view, visit http://gerrit.cloudera.org:8080/16719 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Ief1d6b2c2cb5961c1d6cee1b0eac86ab61509768 Gerrit-Change-Number: 16719 Gerrit-PatchSet: 1 Gerrit-Owner: wesleydeng <[email protected]> Gerrit-Reviewer: Csaba Ringhofer <[email protected]> Gerrit-Reviewer: Gabor Kaszab <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-Reviewer: abeltian <[email protected]> Gerrit-Reviewer: wesleydeng <[email protected]> Gerrit-Comment-Date: Tue, 17 Nov 2020 13:18:42 +0000 Gerrit-HasComments: Yes
