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Hive QA commented on HIVE-20983: -------------------------------- | (/) *{color:green}+1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || || || || || {color:brown} Prechecks {color} || | {color:green}+1{color} | {color:green} @author {color} | {color:green} 0m 0s{color} | {color:green} The patch does not contain any @author tags. {color} | || || || || {color:brown} master Compile Tests {color} || | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 8m 39s{color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 1m 5s{color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 0m 38s{color} | {color:green} master passed {color} | | {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue} 3m 51s{color} | {color:blue} ql in master has 2244 extant Findbugs warnings. {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 0m 55s{color} | {color:green} master passed {color} | || || || || {color:brown} Patch Compile Tests {color} || | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 1m 24s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 1m 1s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} javac {color} | {color:green} 1m 1s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 0m 37s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} whitespace {color} | {color:green} 0m 0s{color} | {color:green} The patch has no whitespace issues. {color} | | {color:green}+1{color} | {color:green} findbugs {color} | {color:green} 3m 59s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 0m 56s{color} | {color:green} the patch passed {color} | || || || || {color:brown} Other Tests {color} || | {color:green}+1{color} | {color:green} asflicense {color} | {color:green} 0m 13s{color} | {color:green} The patch does not generate ASF License warnings. {color} | | {color:black}{color} | {color:black} {color} | {color:black} 23m 48s{color} | {color:black} {color} | \\ \\ || Subsystem || Report/Notes || | Optional Tests | asflicense javac javadoc findbugs checkstyle compile | | uname | Linux hiveptest-server-upstream 3.16.0-4-amd64 #1 SMP Debian 3.16.43-2+deb8u5 (2017-09-19) x86_64 GNU/Linux | | Build tool | maven | | Personality | /data/hiveptest/working/yetus_PreCommit-HIVE-Build-18555/dev-support/hive-personality.sh | | git revision | master / 5b1afb7 | | Default Java | 1.8.0_111 | | findbugs | v3.0.0 | | modules | C: ql U: ql | | Console output | http://104.198.109.242/logs//PreCommit-HIVE-Build-18555/yetus.txt | | Powered by | Apache Yetus http://yetus.apache.org | This message was automatically generated. > Vectorization: Scale up small hashtables, when collisions are detected > ---------------------------------------------------------------------- > > Key: HIVE-20983 > URL: https://issues.apache.org/jira/browse/HIVE-20983 > Project: Hive > Issue Type: Bug > Reporter: Gopal V > Assignee: Mustafa Iman > Priority: Major > Attachments: HIVE-20983.1.patch, HIVE-20983.2.patch > > > Hive's hashtable estimates are getting better with HyperLogLog stats in > place, but an accurate estimate does not always result in a low number of > collisions. > The hashtables which contain a very small number of items tend to lose their > O(1) lookup performance where there are collisions. Since collisions are easy > to detect within the fast hashtable implementation, a rehashing to a higher > size will help these small hashtables avoid collisions and go back to O(1) > perf. -- This message was sent by Atlassian Jira (v8.3.2#803003)