[
https://issues.apache.org/jira/browse/TAJO-742?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Hyunsik Choi updated TAJO-742:
------------------------------
Issue Type: Improvement (was: Sub-task)
Parent: (was: TAJO-727)
> (Umbrella) Theta join support
> -----------------------------
>
> Key: TAJO-742
> URL: https://issues.apache.org/jira/browse/TAJO-742
> Project: Tajo
> Issue Type: Improvement
> Components: physical operator
> Reporter: Jaehwa Jung
> Assignee: Jaehwa Jung
>
> Currently, Tajo supports only equi-join. In contrast, theta-joins (not
> equality join) are used in many real applications. We need to support
> theta-joins in Tajo.
> If a join condition includes anything other than equality predicate "=", we
> call the join *theta join*. The predicates can be as follows:
> * >, >=, <, <=, !=, LIKE. RLIKE, ...
> Basically, some predicates can exploit hash shuffle, range shuffle, or other
> thing. Other predicates requires that only one node processes all
> intermediate data by using BNL. Also, if a join condition is a mixed of
> equi-join and theta-join conditions, this join can make use of hash shuffle.
> This issue requires some investigation.
> This is an umbrella issue. We'll create subtasks.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
