[ https://issues.apache.org/jira/browse/HIVE-2253?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Navis updated HIVE-2253: ------------------------ Attachment: HIVE-2253.4.patch > Merge failing of join tree in exceptional case > ---------------------------------------------- > > Key: HIVE-2253 > URL: https://issues.apache.org/jira/browse/HIVE-2253 > Project: Hive > Issue Type: Bug > Components: Query Processor > Affects Versions: 0.7.0 > Environment: hadoop 0.20.2, hive 0.7.0 > Reporter: Navis > Assignee: Navis > Priority: Minor > Attachments: HIVE-2253.2.patch, HIVE-2253.3.patch, HIVE-2253.4.patch, > HIVE-2253.patch > > > In some very exceptional cases, SemanticAnayzer fails to merge join tree. > Example is below. > create table a (val1 int, val2 int) > create table b (val1 int, val2 int) > create table c (val1 int, val2 int) > create table d (val1 int, val2 int) > create table e (val1 int, val2 int) > 1. all same(single) join key --> one MR, good > select * from a join b on a.val1=b.val1 join c on a.val1=c.val1 join d on > a.val1=d.val1 join e on a.val1=e.val1 > 2. two join keys --> expected to have two MR, but resulted to three MR > select * from a join b on a.val1=b.val1 join c on a.val1=c.val1 join d on > a.val1=d.val1 join e on a.val2=e.val2 > 3. by changing the join order, we could attain two MR as first-expectation. > select * from a join e on a.val2=e.val2 join c on a.val1=c.val1 join d on > a.val1=d.val1 join b on a.val1=b.val1 -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira