[ https://issues.apache.org/jira/browse/HIVE-20332?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16573936#comment-16573936 ]
Hive QA commented on HIVE-20332: -------------------------------- | (x) *{color:red}-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:blue}0{color} | {color:blue} mvndep {color} | {color:blue} 0m 37s{color} | {color:blue} Maven dependency ordering for branch {color} | | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 7m 31s{color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 1m 20s{color} | {color:green} master passed {color} | | {color:green}+1{color} | {color:green} checkstyle {color} | {color:green} 0m 56s{color} | {color:green} master passed {color} | | {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue} 0m 31s{color} | {color:blue} common in master has 64 extant Findbugs warnings. {color} | | {color:blue}0{color} | {color:blue} findbugs {color} | {color:blue} 4m 1s{color} | {color:blue} ql in master has 2305 extant Findbugs warnings. {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 1m 8s{color} | {color:green} master passed {color} | || || || || {color:brown} Patch Compile Tests {color} || | {color:blue}0{color} | {color:blue} mvndep {color} | {color:blue} 0m 9s{color} | {color:blue} Maven dependency ordering for patch {color} | | {color:green}+1{color} | {color:green} mvninstall {color} | {color:green} 1m 43s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} compile {color} | {color:green} 1m 19s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} javac {color} | {color:green} 1m 19s{color} | {color:green} the patch passed {color} | | {color:red}-1{color} | {color:red} checkstyle {color} | {color:red} 0m 40s{color} | {color:red} ql: The patch generated 4 new + 213 unchanged - 1 fixed = 217 total (was 214) {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} 4m 47s{color} | {color:green} the patch passed {color} | | {color:green}+1{color} | {color:green} javadoc {color} | {color:green} 1m 9s{color} | {color:green} the patch passed {color} | || || || || {color:brown} Other Tests {color} || | {color:green}+1{color} | {color:green} asflicense {color} | {color:green} 0m 14s{color} | {color:green} The patch does not generate ASF License warnings. {color} | | {color:black}{color} | {color:black} {color} | {color:black} 27m 5s{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 3.16.36-1+deb8u1 (2016-09-03) x86_64 GNU/Linux | | Build tool | maven | | Personality | /data/hiveptest/working/yetus_PreCommit-HIVE-Build-13107/dev-support/hive-personality.sh | | git revision | master / 3f3d918 | | Default Java | 1.8.0_111 | | findbugs | v3.0.0 | | checkstyle | http://104.198.109.242/logs//PreCommit-HIVE-Build-13107/yetus/diff-checkstyle-ql.txt | | modules | C: common ql U: . | | Console output | http://104.198.109.242/logs//PreCommit-HIVE-Build-13107/yetus.txt | | Powered by | Apache Yetus http://yetus.apache.org | This message was automatically generated. > Materialized views: Introduce heuristic on selectivity over ROW__ID to favour > incremental rebuild > ------------------------------------------------------------------------------------------------- > > Key: HIVE-20332 > URL: https://issues.apache.org/jira/browse/HIVE-20332 > Project: Hive > Issue Type: Improvement > Components: Materialized views > Reporter: Jesus Camacho Rodriguez > Assignee: Jesus Camacho Rodriguez > Priority: Major > Attachments: HIVE-20332.01.patch, HIVE-20332.01.patch, > HIVE-20332.patch > > > Currently, we do not expose stats over {{ROW\_\_ID.writeId}} to the optimizer > (this should be fixed by HIVE-20313). Even if we did, we always assume > uniform distribution of the column values, which can easily lead to > overestimations on the number of rows read when we filter on > {{ROW\_\_ID.writeId}} for materialized views (think about a large transaction > for MV creation and then small ones for incremental maintenance). This > overestimation can lead to incremental view maintenance not being triggered > as cost of the incremental plan is overestimated (we think we will read more > rows than we actually do). This could be fixed by introducing histograms that > reflect better the column values distribution. > Till both fixes are implemented, we will use a config variable that will set > the selectivity for filter condition on {{ROW\_\_ID}} during the cost > calculation. Setting that variable to a low value will favour incremental > rebuild over full rebuild. -- This message was sent by Atlassian JIRA (v7.6.3#76005)