hadoop-pig-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Daniel Dai (JIRA)" <j...@apache.org>
Subject [jira] Updated: (PIG-873) Optimizer should allow search for global patterns
Date Tue, 27 Jul 2010 01:24:17 GMT

     [ https://issues.apache.org/jira/browse/PIG-873?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Daniel Dai updated PIG-873:
---------------------------

    Fix Version/s:     (was: 0.8.0)

> Optimizer should allow search for global patterns
> -------------------------------------------------
>
>                 Key: PIG-873
>                 URL: https://issues.apache.org/jira/browse/PIG-873
>             Project: Pig
>          Issue Type: Improvement
>    Affects Versions: 0.4.0
>            Reporter: Santhosh Srinivasan
>            Assignee: Daniel Dai
>
> Currently, the optimizer works on the following mechanism:
> 1. Specify the pattern to be searched
> 2. For each occurrence of the pattern, check and then apply a transformation
> With this approach, the search for a pattern is localized. An example will illustrate
the problem.
> If the pattern to be searched for is foreach (with flatten) connected to any operator
and if the graph has more than one foreach (with flatten) connected to an operator (cross,
join, union, etc), then each instance of foreach connected to the operator is returned as
a match. While this is fine for a localized view (per match), at a global view the pattern
to be searched for is any number of foreach connected to an operator.
> The implication of not having a globalized view is more rules. There will be one rule
for one foreach connected to an opeator, one rule for two foreachs connected to an operators,
etc.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message