You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@hive.apache.org by "Harish Butani (JIRA)" <ji...@apache.org> on 2014/03/13 00:51:42 UTC
[jira] [Created] (HIVE-6643) Add a check for cross products in
plans and output a warning
Harish Butani created HIVE-6643:
-----------------------------------
Summary: Add a check for cross products in plans and output a warning
Key: HIVE-6643
URL: https://issues.apache.org/jira/browse/HIVE-6643
Project: Hive
Issue Type: Bug
Reporter: Harish Butani
Assignee: Harish Butani
Attachments: HIVE-6643.1.patch
Now that we support old style join syntax, it is easy to write queries that generate a plan with a cross product.
For e.g. say you have A join B join C join D on A.x = B.x and A.y = D.y and C.z = D.z
So the JoinTree is:
A — B
|__ D — C
Since we don't reorder join graphs, we will end up with a cross product between (A join B) and C
--
This message was sent by Atlassian JIRA
(v6.2#6252)